by Ken Task.
The site ID's should be different so me thinks chasing that rabbit is going down a hole.
Could be the 'lmsAdmin' contained in users.xml.
Now I know you have 100+ courses to restore and rebulding a backup excluding that user from the users.xml file contained in the backup extracted isn't something you want to do, but better than loosing 100+ courses.
Could copy one of those backup files to a test directory.
Extract the contents in that test directory.
edit users.xml file and remove the 'lmsAdmin' user. Save the users.xml file
erase the .mbz file in that directory
then rebuild the .mbz file
tar -cvf nameofrebuiltbackup.mbz ./*
The try to restore nameofrebuiltbackup.mbz to a test category using the 'restore_backup.php script to that test category.
If that works, there's your solution ... even though it's time consuming and would probably take many pots of coffee! ![sad]( "sad")
Fingers crossed for ya!
'SoS', Ken