Problems on integration - Received empty response from Moodle

Dear all,
I'm working on integration of Moodle 4.0.4+ and Joomla 3.10.11 using Joomdle 2.0.4 since a few days, but won't still get running.
All settings are made and on the Jommdle System Check in Joomla all points are checked - except the last one: Joomdle Web Service gives the failure 'Received empty response from Moodle'.
I already checked the site www.joomdle.com/wiki/System_health_check...response_from_Moodle , but it wasn't helpful.
Has anybody an idea, how to fix this or what I have to double-check?
Best regards and thanks in advance!

Hi.

Did you check the raw replies to see if there is anything there?
www.joomdle.com/wiki/System_health_check#Raw_replies

Unfortunately not.
joomla_folder/logs/joomdle_system_check.xml dosn't exist
moodledata_folder/temp/joomdle_system_check.xml is not available for me (I'm the site admin, but not the server admin)

I tried this command:
http::/yoursite.com/index.php?option=com_joomdle&task=ws.server&format=xmlrpc
And got this answer:
XML-RPC Error (1): Invalid token:

On this server XML-RPC is not active, it's using REST.
I double-checked the token entries on both sites and I used copy/paste to set the token settings. I can not find any failure.

> On this server XML-RPC is not active, it's using REST.

So, you have selected REST in Joomdle config on both sides, right?

There's not much else I can tell you from here, without taking a look. If you need professional support you can write to antonio at joomdle.

Yes, REST ist selected on both sides.
First I have to get in touch with the server admin - maybe we can find a reason in the logs.
Thanks for your support so far!