Error on upgrade the server with option --ifempty

[BurtGummer]

Hello,

armanager version 1.6 on debian buster, running great since years:

root@sa ~ # arkmanager upgrade-tools
arkmanager v1.6: Checking for updates...
Getting latest release...
Your ARK server tools are already up to date
root@sa ~ #

But now, I got errors on upgrading the mods:

root@sa ~ # arkmanager update @sa5 --ifempty --saveworld --backup --update-mods
Running command 'update' for instance 'sa5'
Checking for update; PID: 4290
/usr/local/bin/arkmanager: Zeile 2112: 0
0 + 0 : Syntaxfehler im Ausdruck. (Fehlerverursachendes Zeichen ist \"0 + 0 \").
root@sa ~ #

I have a cronjob running:

*/20 * * * * root arkmanager update @sa5 --ifempty --saveworld --backup --update-mods >/dev/null 2>&1

Interesting, I try:

root@sa ~ # arkmanager update @sa5 --update-mods --warn
Running command 'update' for instance 'sa5'
Checking for update; PID: 5879
This ARK server will shutdown for an update in 5 minutes
Command processed
There are 0
[...]
/usr/local/bin/arkmanager: Zeile 1899: ((: 0
0: Syntaxfehler im Ausdruck. (Fehlerverursachendes Zeichen ist \"0\").
This ARK server will shutdown for an update in 15 seconds
Command processed
This ARK server will shutdown for an update in 10 seconds
Command processed
This ARK server will shutdown for an update in 5 seconds
Command processed
Stopping server; reason: update
The server has been stopped
Updating mod 731604991
Copying files to /home/steam/5ARK/ShooterGame/Content/Mods/731604991
Mod 731604991 updated
The server is starting...
The server is now running, and should be up within 10 minutes
root@sa ~ #

Any ideas whats wrong?

Edit: Its the option "--ifempty", without this option, everything works.

[klightspeed]

1.6.57 should fix this

[BurtGummer]

Thank you very much! :-)