Well, if this problem happens again, it is almost certain that you have some anti-virus software that blocked DriveHQ Online Backup from accessing your local files / folders. In this case, please stop anti-virus software / security software when you are creating a backup task. After the backup task is created, you can turn on anti-virus again.

If you have another PC, please try it on another PC and see if how it goes. We have a lot of users using Online Backup 4.0; this kind of problem is extremely unlikely by itself. We haven't heard such problem from any other people so far. If you can compare this PC with another PC, you might be able to find the cause more easily.

FYI, starting from Online Backup 4.0, the real backup task is performed by a service process. So even if you close DriveHQ Online Backup 4.0 GUI, or log off your PC, backup can continue running in the background.