I can't generate the target translation after finishing a translation in Studio 2015 SR2

Hi! I received an error message following a failed attempt to generate target translation from Studio 2015 SR2.  It seems the box symbol (there are a lot of them in the file, since it's a survey, so every answer choice starts with the box symbol) might be the culprit, but I am not certain.  Can someone give me some suggestions regarding how to solve this issue?

Thank you so much.  Below is the error message.

Chunyi