Describe the bug
When trying to use the portal gun, the game crashes. This was first reported by @Tromulous over xJon/The-1.12.2-Pack#764.

To Reproduce
Steps to reproduce the behavior:

1. Install the Portal Gun mod, iChunUtil, and Entity Culling.
2. Get a portal gun.
3. Try to use it to summon 2 portals.

Versions
Entity Culling: 4.2.5
Forge: 14.23.5.2860
Minecraft: 1.12.2

Other
Crash report (upload as a file): https://pastebin.com/xsBRsqDr
Singleplayer/Multiplayer: Both
Other mods (that are necessary to produce the bug): Portal Gun, iChunUtil
Other mods (that are also installed): https://www.technicpack.net/modpack/the-1122-pack/mods

Fixed in v1.12.2-5.0.1

Thank you :)