For some time I experienced problems with Skype.

These problems only occurred on my iMac.

Currently my iMac is running macOS Sierra.

I use Skype on a daily basis to conduct standup calls with remote Scrum teams and to contact suppliers.

I noticed that group audio/video calls were not working anymore. Only chats were working.

After googling around and not finding any solution I got the impression it had something to do with my user account and some certificate.

Today I noticed that my machine was slow and I started up Activity monitor. I noticed a background process that was running :

opendirectoryserverd

Surprised as I was that this was running I killed the process and googled for background info on this process.

I found that this process was part of OSX Server.

I remembered that some releases ago I installed OSX server to have a look at it. I did not like it and I do not have a need for the features offered so I deinstalled it with some instructions I found somewhere.

Probably this deinstall was not performed completely and some stuff was still active.

I found this support page to deinstall opendirectoryserver

https://support.apple.com/en-us/HT204880

It seems this corrected my Skype problems.

Fingers crossed!