NOTE: Might be off topic, but this happened to me while trying to report 2018.3 bugs.
Sounds kinda funny but i think there’s a bug in the bug reporter tool. where do i report it? is there a bug reporting tool for the bug reporting tool ?? 
Seriously, though:
The bug reporter does not seem to handle disconnection cases so well.
It had already happened to me a few times before, where i would start uploading a bug report (including a repro project), but since i totally forgot about it, i closed my laptop’s lid and so the upload was halted.
When i opened my laptop again after some time, the upload seemed to be stuck, so i hit “cancel”, but after that the entire bug reporter UI is still disabled and i cannot re-upload the bug report.
This is super annoying as basically all the info i put in (which sometimes takes a bit time!) was lost and i have to do it all over again. sometimes i just don’t have the willpower to do it so i just avoid doing the report again 
Did anyone else face such an issue while reporting bugs? is there any solution?