I've upgraded my laptop to Ubuntu 20.04, and plasmashell is now version 5.18.4. The upgrade appeared to go well, but I have already noticed some problems:

• There is a black bar across the top of my screen with 'Activities', a clock and other stuff; how can I get rid of it?
• I can't configure the pager (it seems to be called 'virtual desktops' any more
• When I try to open 'Virtual Desktops' in System Settings, I see 'There was an error requesting information from the compositor'

That is quite disappointing, I feel - how can I troubleshoot these issues?

janpla wrote:I've upgraded my laptop to Ubuntu 20.04, and plasmashell is now version 5.18.4. The upgrade appeared to go well, but I have already noticed some problems:

[*] There is a black bar across the top of my screen with 'Activities', a clock and other stuff; how can I get rid of it?

Right click on it? You should be able to remove it, I guess it is a panel. Just can't understand why this would be the result of an upgrade, I recently upgraded from Kubuntu 19.10 to 20.04 with no such issues

[*] I can't configure the pager (it seems to be called 'virtual desktops' any more

Right clicked on mine, still called "Virtual desktop Pager" here...

[*] When I try to open 'Virtual Desktops' in System Settings, I see 'There was an error requesting information from the compositor'

That is quite disappointing, I feel - how can I troubleshoot these issues?

Please check you do have indeed a full installation of Plasma, maybe you just miss some components.