Error 121?

[abc]

I am playing with DVDFab 6.2.0.5 and get the following log error. Any ideas? I tried a search for the error number but did not find anything.

08:20:58: You are going to try "DVD to DVD" option.
08:20:59: Analyzing of DVD started
08:21:00: Analyzing of DVD completed successfully
08:21:00: Copy process started
08:36:56: Copy process completed successfully
08:36:56: Create ISO process started
08:47:32: Task_2 failed! Error=121
08:47:33: Process failed!

[W&B]

121 HWS_INVALIDISOPATH 21 // Invalid path for ISO creation