Error running json_path_query

I've been using the json_path_query from the dependencies (io.cloudslang.base.json.json_path_query) for probably 6 months. I have had a lot of successful runs, including many today, but it's now throwing the below error:

Error running: 'json_path_query'. Error evaluating result: 'SUCCESS', Error is: Error in evaluating expression: 'returnCode == '0'', 'charmap' codec can't encode character '\udc9d' in position 627: character maps to <undefined>

But obviously, I have no control over any of the result expressions. The process that I use this in is in Production and is used daily. 

Any ideas?