Unable to use or find anything

[R1NLER]

I have this error, it only happens on some accounts, and I would like to rule out that it's an issue with the webmail. With Outlook, it allows me to function correctly, but in this way, I can't access to search emails (it's used as an email archive).

strtolower(): Passing null to parameter #1 ($string) of type string is deprecated in public_html\oldmail\vendor\afterlogic\mailso\lib\MailSo\Base\Utils.php on line 174

This one is open, but it seems a solution has been provided. I haven't tested it yet.

and

strlen(): Passing null to parameter #1 ($string) of type string is deprecated in public_html\oldmail\vendor\afterlogic\mailso\lib\MailSo\Imap\BodyStructure.php on line 372

[afterlogic-support]

Try adjusting error_reporting value of your PHP configuration so that non-critical messages are suppressed, for example:

error_reporting = E_ALL & ~E_DEPRECATED & ~E_STRICT

Also, you may wish to set display_errors to Off, that way the errors are only logged but aren't displayed in the browser, which is what causes the "Data transfer has failed" message to begin with.

[R1NLER]

I've checked the browser console and I'm receiving these two errors.

This one refers to this line:

                            s.setup && !1 !== s.setup.call(e, n, u, p) || e.addEventListener && e.addEventListener(O, p)),

This other one refers to this.

[afterlogic-support]

Well those message don't seem to be related to the error you've initially reported, they're more of suggestions on the code improvement.