Black triangle in the End?

Please attach the Seed of the world and the coordinates.

-7682097077310318051
I don't know the coordinates, because it's impossible to reach it.

Did you find it?

Useless to search without coordinates.

Can't find the coordinates, it's impossible to reach it, sorry. When you spawn in the End, fly above enough and you will find it.

It is simply a visual glitch, no blocks. Happens to me all the time I go there.

You get this with a low render distance.