In order to fix the problem, I recommend that you update the software to the latest version. Select you version of the program, click Download, save the file to your PC, and install it following the on-screen instructions. After that, launch it, press the Restore button (), select the backup file from the provided list or using the Browse option, and click the 2 button:
In the Step 2 you need to select a directory to restore the backup and then to move to step 3 where you have to select the restoration method (replace the original file, keep it, and so on):
After that, all you need to do is to click Start and then Submit Job:
If you select properly the backup and the restoration directory, there shouldn't appear any "Open file" pop-up window. However, if it appears again, go to the backup folder, select the backup file, and press Open. If you still have problems, I recommend contacting the support team.