I am not able to restore a file from a backup. I get the error code 6000-83. File doctor doesn't fix the issue and neither does renaming the file.
While saving a backup TO a USB thumb drive can go off without a hitch, restoring FROM a USB thumb drive can cause problems and it is wise in such situations to copy.move the backup file to the same hard drive as the program software before restoring.
Additionally, you indicated that you upgraded from 2019 to 2020, Any possibility you are attempting to restore a 2020 backup into 2019? It cannot be done