Ah, I almost never use it myself, so can't comment I'm afraid. It may be some bug or other, so I'll move the thread to the Site Feedback forum, and at the same time ask other team members whether they've encountered the problem.
I have seen something like that sometimes when sending PMs, but it was fixed. Do you know how to do a screen print? Can you screen print the error message and post it here? If you are using Windows it's hold Fn (key) then press) the Insert/Print Screen (key) This will put a copy of your screen in your clipboard you THEN can paste it to MS Paint (or Paint 3D if you are on Win 10), THEN save as a jpeg file and upload it to a message here.
@Ikeman90 - I've seen this on rare occasions as well. Haven't been able to reliably reproduce though
Our tech team IS pushing a bunch of updates to the site this week, so something could be going on there. If the problem persists please do contact me directly and our team will take a closer look!!