CDT Difference Plugin Error

Hey all, we've been seeing an error with the CDT Diff Utilities plugin on occasion (below).  This error occurs sporadically.  In one process we have seen the error occur for ONLY ONE user 25 times, when we reassign that task to another user, they can complete it with the same data with no issues.  The user completes the same tasks regularly, and sometimes the error does not occur.  Data entered is similar.  The error has occurred 25 times for this single user, while they have had 672 successful submissions.  Otherwise, 67 users have completed the same task 16,897 times without issues.

In 2 other medium-use processes the error has occurred one time only each, 1 in a script task set to run as the designer (our admin account) and 1 during a form submission by a different user than the one above.

I see one other post related to this error in the plugin's discussion thread, but no other results via search.  Wondering if anyone else has experienced this error and/or potential resolutions?

Maybe Stewart Burchell can assist?

Thanks!

EDIT:  We are on version 1.1.0 of the plugin, which is current.

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Problem: An invalid expression has been encountered in a task.

Details: An error occurred while evaluating expression: XXX (Expression evaluation error in rule XXX at function 'cdtdifference' [line 37]: XML handling failure trying to convert value com.appiancorp.ps.cdtdiffutils.Difference@1eb0d338 to Appian type Difference (id=3404)) (Data Outputs)