[myron]

When there's an .actor folder in a directory, there must have been a moviefile in same dir.
SInce it looks like the datasource root folder, this is not correct (but might have been for an older version)
If the folder only contains some actor jpegs, i guess it is fine deleteing them.

Moviesets are not a problem; but incorrectly nested video files are.
You might try latest nightly for a fix (ONLY FOR TESTING - not for daily work)
extract to separate dir, start clean