Cannot create Github issue, keeps saying "Unable to create issue" without any other explanation

I've correctly (and fully!) filled in all the fields it wants to, and answered all questions correctly as well. I have no idea whether there is something in the content I wrote (I didn't link outside github's project or anything) or whether the interface has a bug

Anyone here from the devs (or someone else) who can shed some light?

I've hit what looks like a bug.