Endermen xp farms not working?

I've come back to EMC after 2 years and a lot of things have changed. The one I'm mostly confused about is endermen xp farms.
Once apon a time, I could go afk at an enderman farm to come back to a horde of endermen ready to be killed. Using the xp to repair all my damaged tools ect.
But none are spawning now....
Whys this? Am I not waiting long enough?
Ive checked the forums for posts regarding this, but I cannot find one that gives me a straight answer :/

(The endermen farm that i use is one that pushed them off their ledge to the ground)

I know that piston and pushing things are broken, as my wither farm does not work at all so maybe it is the pistons that are causing problems with the farm. That is my best guess

The one I use works fine.

Deshoda, if you are using pistons the problem may be from the anti grief update. Are the pistons pushing a block? If the piston and the block were not laid down by the same person, the anti grief prevents the piston from "griefing" the block by moving it.
If this is not the case, I think we'd need more details to help figure out what's going on at your farm. Luck to you!

I have an entire campaign going on for Enderman Farms - Ender Builder's.

I can tell you for sure that the two farms I've built so far do work fine.

SMP8's Farm is my best one so far. You can get to it right at The End spawn.

https://empireminecraft.com/threads/ender-builders-campaign-for-enderman-farms.52358/


https://www.youtube.com/watch?v=W8aS9kONeL0

Endearment can no longer spawn in tripwires or on pressure plates, the antigriefing update is a thing, and pistons are weird. All of those together probably broke it. Not to hard to fix, just find a tutorial for a 1.8 enderman farm.

Actually, tripwire still allows mob spawns, despite being a redstone component. Mobs have always been able to spawn inside it.

I don't know, I built one recently using an endermite and that didn't work either.

*Prays to God they don't fix that*

The Minecraft developers are well-aware of the consequences to making changes to redstone. They don't want so many already existing creations to break for no better.

Thank you all for posting on my thread, I really appreciate the help
Khixan's response seems like it would be the reason why the farm I use isn't working anymore as its one of Deathtombs endermen farms. Because hes not active anymore to fix this problem, I will probably have to find another way to get experience

mobs do not spawn on pressure plates if that is the issue