Can't login to web control panel

I recently updated from OMV 4 to OMV 5 but it seems something went wrong.

I used that "guide" here:

RE: OMV 5.0 - finally out! :-)

however, when I start the web access panel I can't login anymore.

I get the Login screen but when I proceed I get an error alert stating:

Zitat

Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; hostname --fqdn 2>&1' with exit code '1': hostname: Name or service not known

With the details like that

Error #0:
OMV\ExecException: Failed to execute command 'export PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin; export LANG=C.UTF-8; hostname --fqdn 2>&1' with exit code '1': hostname: Name or service not known in /usr/share/php/openmediavault/system/process.inc:182
Stack trace:
#0 /usr/share/php/openmediavault/system/net/dns.inc(60): OMV\System\Process->execute(Array)
#1 /var/www/openmediavault/rpc/session.inc(124): OMV\System\Net\Dns::getFqdn()
#2 [internal function]: OMVRpcServiceSession->login(Array, Array)
#3 /usr/share/php/openmediavault/rpc/serviceabstract.inc(123): call_user_func_array(Array, Array)
#4 /usr/share/php/openmediavault/rpc/rpc.inc(86): OMV\Rpc\ServiceAbstract->callMethod('login', Array, Array)
#5 /usr/share/php/openmediavault/rpc/proxy/json.inc(97): OMV\Rpc\Rpc::call('Session', 'login', Array, Array, 3)
#6 /var/www/openmediavault/rpc.php(45): OMV\Rpc\Proxy\Json->handle()
#7 {main}

Does anyone have any idea what happened there? I tried to reset things via the omv-firstaid but did not succeed.

Thanks a lot!

Nobody having a hint where to look or what might be wrong?

Okay, I have found out what happened.

When logging in it was calling

hostname -i

which results in that error

Name or service not known

because even though my Hostname seemes to be OMV it wasnt correct. The hostname has the domain attached as suffix. So it was OMV.local instead. I have no Idea why or when that domain got attached but the difference of this to what was written in /etc/hosts seems to be the problem.