You've guided me with your best knowledge but I've only one backup file created by MIGRATE.If it is so, then what I would have done in this situation. See steps below :
1. Go to TWRP and choose to format data partition. Write 'Yes' to go ahead with format data partition.
2. Very important step - Now reboot to recovery.
3. Go ahead with restore data from your backup. (I am presuming that you have data backup on your usb storage, which is being accessed through OTG option in TWRP).
Hopefully, its gonna work for you.