The error screen shots shows there are 126 responses ie 126 pages, 1 per page
Does the same error appear on every page number?
Has the form been modified after receiving submissions (which creates orphan responses)?
Can you purge any orphans and see if it fixes it?
Does the problem happen on a new instance of form wizard?
Can you export the data? In browsing the exported data is there any data that looks unusual?
If it only affects one form instance I would consider exporting all the submission data and then purging it and see if the problem continues.
If you can come up with any repeatable way to cause the problem let me know or email me the form definition. If I could get this to happen on my machine I could figure out what is happening, but looking at the code I can't find anything that explains what is happening in the screen shot.