Error occured while opening file

I am running True Image 2014 Premium, I have been doing differential backups since Sept 30. As of 6 October the differential backup has failed, error while opening file, error code 0xF35F747B3B21F7AE. I took the backup off silent mode and all it allows me it to retry or cancel. Next I get on the log Failed to prepare data stream. Check whether the source or partitions exist, Event Code: 0x000B03E9+0x0004000F+0x00040007+0x0000FFF0+0x80070003. The drive and the is there and can be opened by the restore function and all files visible. I tried looking up the error code to no avail. The depending on the log it gives me Operation has completed with errors, 0x9F2C53C72E8BCD1F. But there is no back up since 6 October. I can't afford to loose anything on this drive, I need my backup to work. What next. Log files attached.