That PHP error means that the file does not exist. The AutoRestore code at code line: 1900 deals with checking files that you have added using the AutoRestore Add Folders & Files tool. So you need to delete those old folders/files that you added for your old site using the AutoRestore Remove Added Folders|Files Search tool. Or you can manually remove/delete all “added files” using similar steps that you used for manually deleting all quarantined files.
Manual deletion steps for AutoRestore Added Files:
1. Turn AutoRestore Off.
2. Delete this folder: /wp-content/bps-backup/autorestore/added-files/
3. Go to BPS Pro-Tools > DB Table Cleaner|Remover > select the “Drop” Radio button next to: the xx_bpspro_arq_add database table and then click the Empty|Drop button.