Hello everyone,
we apologize for your troubles, we've been having some issues with displaying the online content in Cleanup.
However we've made a few fixes in past couple weeks and according to our statistics it is getting better so you should not experience this issue.
If you would still see this dialog, please send us log files so we can analyze what happened on your machine.
You can simply send them by executing our log collector utility from this path C:\Program Files (x86)\AVAST Software\Avast Cleanup\tulogcollector.exe assuming that you have still Avast Cleanup installed on your computer.
Just please add your email address there so we can join the logs with your report here.
Thank you.