Empty UMC following update to UCS 5.0

I know there are several topics on this already but there doesn’t seem to be a solution.
I have two separate UCS environments, both were updated from 4.4.8 to 5.0 and both updates were completed successfully.
One environment is fine, the UMC is populated as it should be, the other environment however has a blank completely blank UMC and the path univention/portal/ doesn’t have a Univention Management Console heading at all, unlike the first environment.

I know I can still access the various items via the univention/management path, but that isn’t fixing the problem!!

Does anyone have any idea what could be causing this, or have an idea of where to start looking?

Further to this, I have just run the update on my file server and I DO have a populated UMC on that, it is just the domain controllers that have an empty UMC.

Also just realised, not sure if this is relevant or not, but the two domain controllers that have the issue are also encrypted, whereas the other systems without the issue aren’t.

Ok, after spending far too long on this I have discovered the cause of the empty UMC, at least in my case.

In the configuration registry the setting ‘apache2/force_https’ must be unset.
I had this set to ‘yes’ on the two DC’s with the issue, however, on the servers without the issue this setting had no value.
After removing the value and running ‘systemctl restart apache2.service’, the UMC is instantly populated correctly.