I think during an upgrade it moves the thumbs folder to a backup and then moves it back. However, I could be wrong.
The bottom line is that the installer expects to find thumbs in a folder called thumbs in the MediaPortal data directory. If you change your setup, you can't be surprised that it gets confused and does something different.
The bottom line is that the installer expects to find thumbs in a folder called thumbs in the MediaPortal data directory. If you change your setup, you can't be surprised that it gets confused and does something different.