I use DOPUS daily on a USB stick (having purchased the relevant licence).
For the sake of having a backup I also keep a copy of the USB stick data/programs on another USB stick. Whenever I upgrade DOPUS on the desktop I also upgrade the USB stick versions of DOPUS on both USB sticks (Menu "Settings...Backup and Restore"). However, I have now seen that DOPUS can actually run only from one of the USB sticks. This means that my backup USB cannot run DOPUS. I understand that this could be for copy protection reasons, but in effect if I'm travelling and my original USB stick has a problem, I would not be able to run DOPUS from the backup USB stick. Is there a possible solution to this potential problem?
If you use Settings -> Backup & Restore to export Opus to two different USB sticks, it should work fine from both of the USB sticks. (You license may only allow 1 USB export, but that's a separate matter.)
Is that what you are doing, or are you exporting to one USB stick and then manually copying the files to another?
I think I may have duplicated the whole original USB stick at some point in order to create the backup version. I'll try exporting DOPUS to each USB stick and see if it will work.
Follow up: I discovered that I had DOPUS installed twice on the backup USB. Once in the root directory and once again as a portable app. After I sorted that out it worked properly.