[OMEMO] Full Description to see and solve bugs: "Myself message", "Missing fingerprints", "Unable to build any sessions, the message was not sent"

Psi+ with 2 XMPP Accounts, and Accounts are in each roster:

OMEMO plugin enabled
First XMPP Account, never OMEMO before (Node has been removed on the server)
Second XMPP Account, has already OMEMO before

EDIT: There are two commits which solve some bugs:

"Forced OMEMO message"
"Toolbar button"

Always here:

"Myself message"
"Missing fingerprints"
"Unable to build any sessions, the message was not sent"

Current problems are:

Myself messages do not work -> "Unable to build any sessions, the message was not sent"
Last one in MUC Room -> "Unable to build any sessions, the message was not sent"
Missing fingerprints for some XMPP contacts
...

Full Description to see and solve bugs:

Starting: 1/ Connection of the First XMPP Account FirstXMPPAccount 2/ Connection of the Second XMPP Account SecondXMPPAccount ...

For my FirstXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> FirstXMPPAccount Account to see "Known Keys":

Nothing, empty

For my SecondXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> SecondXMPPAccount Account to see "Known Keys":

Own Device IDs/Fingerprints are trusted
No FirstXMPPAccount Account Device ID/Fingerprint

After "1", I have looked: For my FirstXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> FirstXMPPAccount Account to see "Known Keys":

FirstXMPPAccount Device ID/Fingerprint, "not decided"
SecondXMPPAccount Device IDs/Fingerprints, "not decided"

I have not touched to trust fingerprints.

For my SecondXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> SecondXMPPAccount Account to see "Known Keys":

Own Device IDs/Fingerprints are trusted
No FirstXMPPAccount Account Device ID/Fingerprint

My SecondXMPPAccount is offline here but I see in XML Console of FirstXMPPAccount Account:

<message from="secondxmppaccount@domain2.tld" to="firstxmppaccount@domain1.tld/Psi+" type="headline" id="AGENERATEDID">
<event xmlns="http://jabber.org/protocol/pubsub#event">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID2XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="1ITEMID2XMPPACCOUNT"/>
   <device id="2ITEMID2XMPPACCOUNT"/>
   <device id="3ITEMID2XMPPACCOUNT"/>
   <device id="4ITEMID2XMPPACCOUNT"/>
   <device id="5ITEMID2XMPPACCOUNT"/>
  </list>
</item>
</items>
</event>
<delay xmlns="urn:xmpp:delay" stamp="XXXX-XX-XXTXX:XX:XXZ"/>
</message>

<presence from="secondxmppaccount@domain2.tld" to="firstxmppaccount@domain1.tld/Psi+" type="unavailable">
<status>Logged out</status>
<delay xmlns="urn:xmpp:delay" stamp="XXXX-XX-XXTXX:XX:XXZ" from="domain2.tld"/>
</presence>

After "2", SecondXMPPAccount Account is connected, I have looked: Same that before: For my FirstXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> FirstXMPPAccount Account to see "Known Keys":

FirstXMPPAccount Device ID/Fingerprint, "not decided"
SecondXMPPAccount Device IDs/Fingerprints, "not decided"

I have not touched to trust fingerprints.

For my SecondXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> SecondXMPPAccount Account to see "Known Keys":

Own Device IDs/Fingerprints are trusted
No FirstXMPPAccount Account Device ID/Fingerprint (PROBLEM here)

My SecondXMPPAccount in XML Console:

<presence from="firstxmppaccount@domain1.tld/Psi+" to="secondxmppaccount@domain2.tld">
<show>away</show>
<priority>10</priority>
<c xmlns="http://jabber.org/protocol/caps" node="https://psi-plus.com" ver="CAPSVER" hash="sha-1"/>
</presence>

My FirstXMPPAccount in XML Console:

<presence from="secondxmppaccount@domain2.tld/Psi+" to="firstxmppaccount@domain1.tld">
<show>away</show>
<priority>100</priority>
<c xmlns="http://jabber.org/protocol/caps" node="https://psi-plus.com" ver="CAPSVER" hash="sha-1"/>
<x xmlns="vcard-temp:x:update">
<photo>AVATARSECONDXMPPACCOUNT</photo>
</x>
</presence>

SecondXMPPAccount Account, when I open the tab to talk with FirstXMPPAccount Account: OMEMO GREY ICON. I can see in SecondXMPPAccount XML Console that my SecondXMPPAccount Account detects OMEMO for my FirstXMPPAccount (but OMEMO GREY ICON):

<iq id='ID1' from='secondxmppaccount@domain2.tld' to='firstxmppaccount@domain1.tld' type='get'>
<pubsub xmlns='http://jabber.org/protocol/pubsub'>
<items node='eu.siacs.conversations.axolotl.devicelist'/>
</pubsub>
</iq>

<iq from="firstxmppaccount@domain1.tld" to="secondxmppaccount@domain2.tld/Psi+" type="result" id="ID1">
<pubsub xmlns="http://jabber.org/protocol/pubsub">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID1XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="FirstXMPPAccountCURRENTDEVICEID"/>
  </list>
</item>
</items>
</pubsub>
</iq>

FirstXMPPAccount Account, when I open the tab to talk with SecondXMPPAccount Account, OMEMO RED ICON (showed but I have not enabled). I can see in FirstXMPPAccount XML Console that my SecondXMPPAccount detects OMEMO for my SecondXMPPAccount:

<iq id='ID2' from='firstxmppaccount@domain1.tld' to='secondxmppaccount@domain2.tld' type='get'>
<pubsub xmlns='http://jabber.org/protocol/pubsub'>
<items node='eu.siacs.conversations.axolotl.devicelist'/>
</pubsub>
</iq>

<iq from="secondxmppaccount@domain2.tld" to="firstxmppaccount@domain1.tld/Psi+" type="result" id="ID2">
<pubsub xmlns="http://jabber.org/protocol/pubsub">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID2XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="1ITEMID2XMPPACCOUNT"/>
   <device id="2ITEMID2XMPPACCOUNT"/>
   <device id="3ITEMID2XMPPACCOUNT"/>
   <device id="4ITEMID2XMPPACCOUNT"/>
   <device id="5ITEMID2XMPPACCOUNT"/>
  </list>
</item>
</items>
</pubsub>
</iq>

FirstXMPPAccount Account, when I open the tab to talk with myself, OMEMO RED ICON (showed but I have not enabled). I can see in FirstXMPPAccount XML Console that my FirstXMPPAccount detects myself OMEMO:

<iq id='ID3' from='firstxmppaccount@domain1.tld' to='firstxmppaccount@domain1.tld' type='get'>
<pubsub xmlns='http://jabber.org/protocol/pubsub'>
<items node='eu.siacs.conversations.axolotl.devicelist'/>
</pubsub>
</iq>

<iq from="firstxmppaccount@domain1.tld" to="firstxmppaccount@domain1.tld/Psi+" type="result" id="ID3">
<pubsub xmlns="http://jabber.org/protocol/pubsub">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID1XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="FirstXMPPAccountCURRENTDEVICEID"/>
  </list>
</item>
</items>
</pubsub>
</iq>

After it, SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON (showed but I have not enabled) // PROBLEM here: it is OMEMO FORCED - I HAVE NOT ENABLED I try to send an unencrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:09] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:09] <SecondXMPPAccount Account> .

After it, FirstXMPPAccount Account tab to talk with SecondXMPPAccount Account: OMEMO RED ICON (showed but I have not enabled). I try to send an unencrypted message from FirstXMPPAccount to SecondXMPPAccount, no problem here:

In the FirstXMPPAccount tab:

[XX:XX:40] <FirstXMPPAccount Account> ..

FirstXMPPAccount XML Console:

<message to="secondxmppaccount@domain2.tld/Psi+" type="chat" id="ID4">
<body>..</body>
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
</message>

<message from="secondxmppaccount@domain2.tld/Psi+" to="firstxmppaccount@domain1.tld/Psi+" id="ID5">
<received xmlns="urn:xmpp:receipts" id="ID4"/>
</message>

In the SecondXMPPAccount tab:

[XX:XX:40] <FirstXMPPAccount Account> ..

SecondXMPPAccount XML Console:

<message from="firstxmppaccount@domain1.tld/Psi+" to="secondxmppaccount@domain2.tld/Psi+" type="chat" id="ID4">
<body>..</body>
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
</message>

<message to="firstxmppaccount@domain1.tld/Psi+" id="ID5">
<received xmlns="urn:xmpp:receipts" id="ID4"/>
</message>

After it, SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON (showed but I have not enabled) // PROBLEM ALWAYS here: it is OMEMO FORCED - I HAVE NOT ENABLED A new time, I try to send an unencrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:15] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:15] <SecondXMPPAccount Account> .

NOTE: Same that before: For my FirstXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> FirstXMPPAccount Account to see "Known Keys":

FirstXMPPAccount Device ID/Fingerprint, "not decided"
SecondXMPPAccount Device IDs/Fingerprints, "not decided"

I have not touched to trust fingerprints.

For my SecondXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> SecondXMPPAccount Account to see "Known Keys":

Own Device IDs/Fingerprints are trusted
No FirstXMPPAccount Account Device ID/Fingerprint (PROBLEM here)

After it, SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON -> "Enable OMEMO Encryption" // ANOTHER PROBLEM here. I have now a dialog window "Managing of OMEMO keys": New OMEMO device has been discovered for "FirstXMPPAccount Account". Do you want to trust this device and allow it to receive the encrypted messages from you? Device public key: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX

NO XML Change, it was in Psi+ memory!

For my SecondXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> SecondXMPPAccount Account to see "Known Keys":

Own Device IDs/Fingerprints are trusted
No FirstXMPPAccount Account Device ID/Fingerprint (PROBLEM ALWAYS here: I HAVE SELECTED "Enable OMEMO Encryption" in SecondXMPPAccount Account tab talk with FirstXMPPAccount Account)

For my FirstXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> FirstXMPPAccount Account to see "Known Keys":

FirstXMPPAccount Device ID/Fingerprint, "Trusted" (PROBLEM here)
SecondXMPPAccount Device IDs/Fingerprints, "not decided"

After it, always SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON (Enabled) // ALWAYS PROBLEM here. I try to send an OMEMO encrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:30] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:30] <SecondXMPPAccount Account> .

After it, FirstXMPPAccount Account tab to talk with myself, I see another PROBLEM here: OMEMO RED ICON AND IT HAS BEEN ENABLED BUT I HAVE NOT DO THIS, CONFLICT WITH THE OTHER TAB: SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account. I try to send an OMEMO encrypted message to myself, nothing in XML Console of FirstXMPPAccount, but in the tab:

[XX:XX:50] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:50] <SecondXMPPAccount Account> .

After it, FirstXMPPAccount Account tab to talk with myself, I disable OMEMO Encryption (OMEMO RED ICON). I send an unencrypted message, no problem here:

In the tab:

[XX:XX:12] <FirstXMPPAccount Account> ..
[XX:XX:13] <FirstXMPPAccount Account> ..

FirstXMPPAccount XML Console:

<message to="firstxmppaccount@domain1.tld/Psi+" type="chat" id="ID6">
<body>..</body>
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
</message>

<message from="firstxmppaccount@domain1.tld/Psi+" to="firstxmppaccount@domain1.tld/Psi+" type="chat" id="ID6">
<body>..</body>
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
</message>

<message to="firstxmppaccount@domain1.tld/Psi+" id="ID7">
<received xmlns="urn:xmpp:receipts" id="ID6"/>
</message>

<message from="firstxmppaccount@domain1.tld/Psi+" to="firstxmppaccount@domain1.tld/Psi+" id="ID7">
<received xmlns="urn:xmpp:receipts" id="ID6"/>
</message>

After it, SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON (showed but I have not enabled) // ANOTHER PROBLEM here. OMEMO RED ICON AND IT HAS BEEN DISABLED BUT I HAVE NOT DO THIS, CONFLICT WITH THE OTHER TAB: FirstXMPPAccount Account tab to talk with SecondXMPPAccount Account. I try to send an unencrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:03] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:03] <SecondXMPPAccount Account> ...

After it, FirstXMPPAccount Account tab to talk with SecondXMPPAccount Account: OMEMO RED ICON (showed but I have not enabled) I try to send an unencrypted message from FirstXMPPAccount to SecondXMPPAccount, no problem here:

In the FirstXMPPAccount tab:

[XX:XX:36] <FirstXMPPAccount Account> ..

FirstXMPPAccount XML Console:

<message to="secondxmppaccount@domain2.tld/Psi+" type="chat" id="ID8">
<body>..</body>
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
</message>

<message from="secondxmppaccount@domain2.tld/Psi+" to="firstxmppaccount@domain1.tld/Psi+" id="ID9">
<received xmlns="urn:xmpp:receipts" id="ID8"/>
</message>

In the SecondXMPPAccount tab:

[XX:XX:36] <FirstXMPPAccount Account> ..

SecondXMPPAccount XML Console:

<message from="firstxmppaccount@domain1.tld/Psi+" to="secondxmppaccount@domain2.tld/Psi+" type="chat" id="ID8">
<body>..</body>
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
</message>

<message to="firstxmppaccount@domain1.tld/Psi+" id="ID9">
<received xmlns="urn:xmpp:receipts" id="ID8"/>
</message>

After it, FirstXMPPAccount Account tab to talk with SecondXMPPAccount Account: OMEMO RED ICON -> "Enable OMEMO Encryption" I have now a dialog window "Managing of OMEMO keys" by DEVICE: New OMEMO device has been discovered for "SecondXMPPAccount Account". Do you want to trust this device and allow it to receive the encrypted messages from you? Device public key: XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX XXXXXXXX

NO XML Change, it was in Psi+ memory!

For my SecondXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> SecondXMPPAccount Account to see "Known Keys":

Own Device IDs/Fingerprints are trusted
No FirstXMPPAccount Account Device ID/Fingerprint (PROBLEM ALWAYS here)

For my FirstXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> FirstXMPPAccount Account to see "Known Keys":

FirstXMPPAccount Device ID/Fingerprint, "Trusted"
SecondXMPPAccount Device IDs/Fingerprints, "Trusted"

After it, FirstXMPPAccount Account tab to talk with SecondXMPPAccount Account: OMEMO RED ICON (Enabled). I try to send an OMEMO encrypted message from FirstXMPPAccount to SecondXMPPAccount, no problem here (except "[OMEMO] The following message is from an untrusted device:" in SecondXMPPAccount tab)

In the FirstXMPPAccount tab:

[XX:XX:45] ***  OMEMO encryption is enabled
[XX:XX:45] <FirstXMPPAccount Account> ..

FirstXMPPAccount XML Console:

<message to="secondxmppaccount@domain2.tld/Psi+" type="chat" id="ID10">
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
<encrypted xmlns="eu.siacs.conversations.axolotl">
<header sid="FirstXMPPAccountCURRENTDEVICEID">
<iv>OMEMOIV</iv>
<key prekey="true" rid="1ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="2ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="3ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="4ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="5ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
</header>
<payload>PAYLOAD</payload>
</encrypted>
<store xmlns="urn:xmpp:hints"/>
<encryption xmlns="urn:xmpp:eme:0" namespace="eu.siacs.conversations.axolotl"/>
<body>You received a message encrypted with OMEMO but your client doesn't support OMEMO or its support is currently disabled.</body>
</message>

<message from="secondxmppaccount@domain2.tld/Psi+" to="firstxmppaccount@domain1.tld/Psi+" id="ID11">
<received xmlns="urn:xmpp:receipts" id="ID10"/>
</message>

In the SecondXMPPAccount tab:

[XX:XX:48] *** [OMEMO] The following message is from an untrusted device:
[XX:XX:48] ***  OMEMO encryption is enabled
[XX:XX:48] <FirstXMPPAccount Account> ..

SecondXMPPAccount XML Console:

<message from="firstxmppaccount@domain1.tld/Psi+" to="secondxmppaccount@domain2.tld/Psi+" type="chat" id="ID10">
<active xmlns="http://jabber.org/protocol/chatstates"/>
<request xmlns="urn:xmpp:receipts"/>
<encrypted xmlns="eu.siacs.conversations.axolotl">
<header sid="FirstXMPPAccountCURRENTDEVICEID">
<iv>OMEMOIV</iv>
<key prekey="true" rid="1ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="2ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="3ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="4ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
<key prekey="true" rid="5ITEMID2XMPPACCOUNT">XXXXXXXXXXXXXXXXXXXXXXXXX</key>
</header>
<payload>PAYLOAD</payload>
</encrypted>
<store xmlns="urn:xmpp:hints"/>
<encryption xmlns="urn:xmpp:eme:0" namespace="eu.siacs.conversations.axolotl"/>
<body>You received a message encrypted with OMEMO but your client doesn't support OMEMO or its support is currently disabled.</body>
</message>

<iq id='ID12' from='secondxmppaccount@domain2.tld' to='firstxmppaccount@domain1.tld' type='get'>
<pubsub xmlns='http://jabber.org/protocol/pubsub'>
<items node='eu.siacs.conversations.axolotl.devicelist'/>
</pubsub>
</iq>

<message to="firstxmppaccount@domain1.tld/Psi+" id="ID11">
<received xmlns="urn:xmpp:receipts" id="ID10"/>
</message>

<iq from="firstxmppaccount@domain1.tld" to="secondxmppaccount@domain2.tld/Psi+" type="result" id="ID12">
<pubsub xmlns="http://jabber.org/protocol/pubsub">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID1XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="FirstXMPPAccountCURRENTDEVICEID"/>
  </list>
</item>
</items>
</pubsub>
</iq>

After it, SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON (showed but I have not enabled) // ANOTHER PROBLEM here. OMEMO RED ICON AND ALWAYS DISABLED, CONFLICT WITH THE OTHER TAB: FirstXMPPAccount Account tab to talk with SecondXMPPAccount Account. I try to send an unencrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:20] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:20] ***  Encryption is disabled
[XX:XX:20] <SecondXMPPAccount Account> ...

After it, SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON -> "Enable OMEMO Encryption" // ANOTHER PROBLEM here. I try to send an OMEMO encrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:20] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:20] ***  Encryption is disabled
[XX:XX:20] <SecondXMPPAccount Account> ...

After it, SecondXMPPAccount Account tab to talk with FirstXMPPAccount Account: OMEMO RED ICON -> "Disable OMEMO Encryption" // ANOTHER PROBLEM here. I try to send an unencrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:40] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:40] <SecondXMPPAccount Account> ...

After it, FirstXMPPAccount Account tab to talk with myself: OMEMO RED ICON -> "Enable OMEMO Encryption" // ANOTHER PROBLEM here. I try to send an OMEMO encrypted message to myself, nothing in XML Console of FirstXMPPAccount, but in the tab:

[XX:XX:52] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:52] <FirstXMPPAccount Account> ...

Same that before: For my SecondXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> SecondXMPPAccount Account to see "Known Keys":

Own Device IDs/Fingerprints are trusted
No FirstXMPPAccount Account Device ID/Fingerprint (PROBLEM ALWAYS here)

For my FirstXMPPAccount Account: In Psi+ -> Options -> Plugins -> OMEMO -> Options -> FirstXMPPAccount Account to see "Known Keys":

FirstXMPPAccount Device ID/Fingerprint, "Trusted"
SecondXMPPAccount Device IDs/Fingerprints, "Trusted"

I have closed all

FirstXMPPAccount Account Connection:

XML Console:

<iq id='ID13' from='firstxmppaccount@domain1.tld' to='firstxmppaccount@domain1.tld' type='get'>
<pubsub xmlns='http://jabber.org/protocol/pubsub'>
<items node='eu.siacs.conversations.axolotl.devicelist'/>
</pubsub>
</iq>

<iq from="firstxmppaccount@domain1.tld" id="ID13" type="result" to="firstxmppaccount@domain1.tld/Psi+">
<pubsub xmlns="http://jabber.org/protocol/pubsub">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID1XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="FirstXMPPAccountCURRENTDEVICEID"/>
  </list>
</item>
</items>
</pubsub>
</iq>

<message from="secondxmppaccount@domain2.tld" id="AGENERATEDID" type="headline" to="firstxmppaccount@domain1.tld/Psi+">
<event xmlns="http://jabber.org/protocol/pubsub#event">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID2XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="1ITEMID2XMPPACCOUNT"/>
   <device id="2ITEMID2XMPPACCOUNT"/>
   <device id="3ITEMID2XMPPACCOUNT"/>
   <device id="4ITEMID2XMPPACCOUNT"/>
   <device id="5ITEMID2XMPPACCOUNT"/>
  </list>
</item>
</items>
</event>
<delay xmlns="urn:xmpp:delay" stamp="XXXX-XX-XXTXX:XX:XXZ"/>
</message>

<message from="firstxmppaccount@domain1.tld" id="AGENERATEDID" to="firstxmppaccount@domain1.tld/Psi+">
<event xmlns="http://jabber.org/protocol/pubsub#event">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID1XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="FirstXMPPAccountCURRENTDEVICEID"/>
  </list>
</item>
</items>
</event>
<delay xmlns="urn:xmpp:delay" stamp="XXXX-XX-XXTXX:XX:XXZ"/>
<addresses xmlns="http://jabber.org/protocol/address">
<address jid="firstxmppaccount@domain1.tld/Psi+" type="replyto"/>
</addresses>
</message>

<message from="firstxmppaccount@domain1.tld" id="AGENERATEDID" to="firstxmppaccount@domain1.tld/Psi+">
<event xmlns="http://jabber.org/protocol/pubsub#event">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID1XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="FirstXMPPAccountCURRENTDEVICEID"/>
  </list>
</item>
</items>
</event>
<delay xmlns="urn:xmpp:delay" stamp="XXXX-XX-XXTXX:XX:XXZ"/>
<addresses xmlns="http://jabber.org/protocol/address">
<address jid="firstxmppaccount@domain1.tld/Psi+" type="replyto"/>
</addresses>
</message>

SecondXMPPAccount Connection:

SecondXMPPAccount XML Console:

<presence from="firstxmppaccount@domain1.tld/Psi+" to="secondxmppaccount@domain2.tld">
<show>away</show>
<priority>10</priority>
<c xmlns="http://jabber.org/protocol/caps" node="https://psi-plus.com" hash="sha-1" ver="CAPSVER"/>
</presence>

FirstXMPPAccount XML Console:

<presence from="secondxmppaccount@domain2.tld/Psi+" to="firstxmppaccount@domain1.tld">
<show>away</show>
<priority>100</priority>
<c xmlns="http://jabber.org/protocol/caps" node="https://psi-plus.com" hash="sha-1" ver="CAPSVER"/>
<x xmlns="vcard-temp:x:update">
<photo>AVATARSECONDXMPPACCOUNT</photo>
</x>
</presence>

SecondXMPPAccount Account, when I open the tab to talk with FirstXMPPAccount Account: OMEMO GREY ICON // PROBLEM here, THERE WAS OMEMO RED ICON BEFORE BUT DID NOT WORK. I can see in SecondXMPPAccount XML Console that my SecondXMPPAccount Account detects OMEMO for my FirstXMPPAccount (but OMEMO GREY ICON):

<iq id='ID14' from='secondxmppaccount@domain2.tld' to='firstxmppaccount@domain1.tld' type='get'>
<pubsub xmlns='http://jabber.org/protocol/pubsub'>
<items node='eu.siacs.conversations.axolotl.devicelist'/>
</pubsub>
</iq>

<iq from="firstxmppaccount@domain1.tld" id="ID14" type="result" to="secondxmppaccount@domain2.tld/Psi+">
<pubsub xmlns="http://jabber.org/protocol/pubsub">
<items node="eu.siacs.conversations.axolotl.devicelist">
<item id="ITEMID1XMPPACCOUNT">
<list xmlns="eu.siacs.conversations.axolotl">
   <device id="FirstXMPPAccountCURRENTDEVICEID"/>
  </list>
</item>
</items>
</pubsub>
</iq>

GREY OMEMO ICON, I try to send an unencrypted message from SecondXMPPAccount to FirstXMPPAccount, nothing in XML Console of SecondXMPPAccount and FirstXMPPAccount, but in the tab:

[XX:XX:43] *** [OMEMO] Unable to build any sessions, the message was not sent
[XX:XX:43] <SecondXMPPAccount Account> ...

psi-im / plugins

[OMEMO] Full Description to see and solve bugs: "Myself message", "Missing fingerprints", "Unable to build any sessions, the message was not sent" #111