The error message gives several possible causes, and all need to be researched.

Connect with Sage support via Live Chat if you are using Timeslips Premium, and we can help you track down your specific issue.

Most likely, that error is not caused by Sage. 

The most frequent cause of that error I have encountered is disk quotas.  Whoever setup your network may have said something like, "each user can use  one gigabyte of space" (or some similar number).  For most people, this is more than ample, but Timeslips database backups are large and frequent.  Over time you will reach your limit, whatever that limit is.  This would explain why it worked yesterday and not today.  Disk Quotas are controlled by Windows or your server, not Timeslips.

A second option to check is the permissions on the backup folder. Should you lose write permission to the backup folder, it would also create that error message. Again, this is controlled by Windows or your server, not Timeslips

Thank you.

Michael Klein
Computer Directions, Inc.

Timeslips Certified Consultant since 1985
Coauthor of the Book "Advanced Windows Business Server"
Two Time Winner ChannelPro Magazine's 20/20 Visionary award

Thanks so much for replying Michael, much appreciated.  I've forwarded your response to our IT team.  I'll let you know the outcome.