Hey, So was having an issue with creating new backups from the manual button on the WebUi, and also weith the cron job. It took me a while to figure out the issue, first thought it was permissions issues that all the other threads say thats causing this issue. Turns out it was an issue with the Rdiff folder inside the server folder that was causing a conflic issue, so after removing the folder in the server folder I was able to run the button in the UI and have it succed.
Thought there would be other people out there with my issue.
Let me know if this is in the wrong catagory.