Sage 50–Automatic Backup – An unknown error occurred compressing the database files.

While setting up a new Sage 50 2015 server I kept getting an error message “An unknown error occurred compressing the database files.” After further troubleshooting with Microsoft Process Monitor (https://technet.microsoft.com/en-us/library/bb896645.aspx) I found that it was trying to put a temporary file in a folder called “Backup” inside the company folder. This is probably a rare condition and only seen if you try to select a backup folder other than the default.

Simply create a folder called “Backup” in the company folder and try it again.