With B4A 8.00 I'm getting frequent error messages about "Directory is not empty." It's currently happening when I try to Project/Choose Icon - and the directory concerned is ..\objects\gen\android.
It also happens when I try to Run under debug or release mode.
The solution has been to delete everything in Objects and restart B4A, which is very annoying when there was no problem with my previous version of B4A.
My project is on a OneDrive folder - but I've not changed anything between B4A versions.
I'm having the same problem I copied the folder from onedrive to desktop and it was ok so it looks like a onedrive problem.
This only started today after a windows update.
Dave.
Don't have the drive sync software running when developing. It and B4A are trying to work with the same files and one is preventing the other from doing what it was designed to do.
Yes, in the past I used the local Dropbox folder and eventually I would run into similar problems.
Don't use onedrive, Dropbox for your active source folder. Set up another folder and then when you have finished copy your project to the synchronized folder or even better use Git on your PC and let it sync.
Same for me, I use OneDrive too, but what I do is Pause the Syncing when developing, and then Restart it when I'm done (or when going to get a coffee etc).