I have experienced this on my server multiple times were you can go near the border and stack crystals constantly which then leads to a server crash. Is there any fix?
Yes, though they do advise not to use this and use the JIRA. Anyways, question unanswered: what is stacking crystals?
If you go to the border any side you can stand under like obsidian and place crystals on top of each other
My server is offline at the moment and by crystals i mean ender crystals which are commonly used for PvP in 1.11 now
Okay, do you mean that you can place ender crystals outside of the border? Do you mind listing your plugins?
No you can place them on top of each other which i will demonstrate in a minute when MC loads. And it is not a plugin causing it as i will demonstrate on a plain spigot server
I have no clue. i don't think that's a spigot bug, try it in a singleplayer world and if it continues submit a bug for minecraft here By the way you were supposed to put this into IMG: Code (Text): http://image.prntscr.com/image/17542a0c2df94b6c871614b1fcb98bed.png
This is a problem that simply can't be solved easily. You can also try placing a few thousands of minecarts or armor stands and see if they will lag the server.
This is normal; players are not even meant to be able to get end crystals, let alone place them. They are entities, not blocks. The only way to place them is with /summon or similar, and like all entities, they can stack.
