Black screen issue
You might find more answers over in the Tech Support sub-forum, as that is where issues such as yours are addressed. You can also, if you so desire, submit a Tech Support ticket to the TCS Team for assistance. Top of Page – Support – Submit a Request.
Oh, and there is this, as well: https://forum-en.gw2archive.eu/forum/support/tech/Black-Screen-Issues-1
Good luck.