I am also experiencing this problem. I followed various instructions here to no avail. I deleted all existing databases. I loaded my preferred database and looked at Collection Statistics. I used the Save to Web function under the Print menu to upload various lists to the server and received the acknowledgement that they were uploaded. I used the functions in Sidekick to update the database content, optimize the database and save it to the cloud. I now can only call up the name of my database in the mobile app but no reports appear with it. I've done all these things several times in different order, just in case that was the issue.
This began happening when I downloaded one of the last big updates and I've been holding out hoping that a more recent update would fix the problem. It has not.
Also, everytime I open the ComicBase, an error message appears. I have attached the window that opens. When I press the OK button the program loads. Is this an indicator of the problem?
Please help. This should NOT be this hard.