I am having similar problem. I use Debian 8 with Moodle 3.2.1, OpenMeetings 3.2, OpenMeetings Module 2.0.0.6 (so every part of this system is in the latest version, installed on the same server).
I can login to OM directly, everything is working fine.
However I can't connect to OM via Moodle module. I've created a OM user named 'moodle' with following configuration:
Of course login and password of OM user are properly configured in Moodle module settings.
And: while entering a OpenMeetings module, I see an Moodle page, with Openmeetings embedded in iframe, but instead of a OM room page, I can see a OM login page, as showed on image:
Changing OM 'moodle' user parameter "Type" to anything else but "user" results in receiving following error:
"Error While signing into OpenMeetings, please check credentials
-10
Could not login User to OpenMeetings, check your OpenMeetings Module Configuration"
While I change a OM user password to wrong, the error code is -11, so the basic communication between Moodle and OM is working.
OM / red5 logs doesn't provide any useful info of this issue.
Any ideas?