I placed a rope under a giant mushroom and it crashed me, now the world is corrupted.

CLosing since lack of response and probably incompatibility with Optifine

A crash log would be nice.

oh i didnt include one? Sorry I thought I did.

Doesn't placing ropes under the brown mushroom blocks cause it? I'm not with my pc at so i cant cause it yet.

I'm guessing @jawsawn simply has OptiFine installed, which does cause some mods that don't support it to crash (with the mushroom being unrelated). To fix the world, try loading it with OptiFine disabled to remove the rope.

Here's a crash report.

Minecraft 1.9.4
Forge 1.9.4-12.17.0.1951
OptiFine 1.9.4_HD_U_B5
NinjaGear 1.9.4-0.0.2

If this is truly Optifine related, then sorry I can't and won't do anything. None of my mods support Optifine, and they never will.
If it still crashes without Optifine, then I will need a crash log.