I’m scared. I got a read warning, backend not accessible. Subsequent run ran fine though.
When I checked the log I’ve seen that the number of files examined increased (to be expected), yet file add remained 0.
If these are files that you have in locations where you know the files there are to be backed up, then yes its failing to backup and you need to take action.
I would just do a new backup or use a different application depending on your level of pissed off 
You can try to solve this issue. Don’t know why backend not accessible would be happening. That could be in reference to a few things.
Did you set any advanced settings? That can cause all green on the backups but just push a warning.