Backup Failed: Failed to Mount Windows Share when connecting iPhone 5 with iOS 9.0.2

When I try to connect my iPhone 5 (running iOS 9.0.2) to my Ubuntu (12.04), I do not get an endless "Trust this computer?" loop, but instead, a single window popping up that says "Backup Failed: Failed to Mount Windows Share."

I haven't been able to find any posts on here about this issue. Can anyone help?