I'm not sure if this is a bug, but lately whenever I dupe a report and add written information, (I've replicated this three times now) it says (and i quote) "There was an error writing your reasoning, but the report was still duplicated. (1)" I've never seen this before, and I'm not using any add-ons or anything either.
Here's the screenshot of the message:
https://imgur.com/a/658ogf1