When attempting to restore a backup (.4BK) file, an error may be encountered that states the following:

File “MyApp[xxxx].4BK.1” not found

Where “MyApp” is the name of the application and “xxxx” is the backup number. This error can occur when backup files are segmented, and additional backup file segments are expected. In this case, the ".1" refers to the first segment. Check in the Backup structure settings (Backup & Restore > Archive) to see if the backup files are being segmented.