Tristan it does this when there is a backup error. you can delete those folders. you are probably running out of room. I added a 6tb hard drive and moved everything over to it. The one issue is that with AC you can't keep AC from making a backup file in the Back up folder in ACbackups. you can add a second place to make a file but you can't keep it from the main drive.
I found after all the work of moving everything that my biggest issue is in the temp folder for my server i needed to clear it out!!!!
you may not need to make the server change...we can talk privately if you want.
