Cyclic Machinery Ticking Server Exception Crash (ConcurrentModificationException)

[mklprudence]

Bug Report

Multiple occurrence of the Java ConcurrentModificationException has shown up when I was interacting with Cyclic machinery causing the whole client to crash. (6 crashes from Experience Pylon, and 8 crashes from Fan, up to this point) In all 14 crashes, I was interacting with the GUI (clicking +500 button to extract XP, and clicking slider to change Fan range / speed)

Expected Behaviour

To give me the XP and change Fan setting, instead of crashing the client

Steps to Reproduce (for bugs)

1. Using Cyclic machines a lot in a short amount of time
2. Actions that causes me to crash: (i) Changing "Fan" settings of multiple fan in a short period of time (ii) Adding experience to myself in the "Experience Pylon" by clicking the +500 button

Logs

• Client/Server Log: https://gist.github.com/mklprudence/fe8e80d112e7d8738482eff527f97fd2
• Crash Log: https://pastebin.com/CfsQSYx6

World Information

• Preset: Sky Factory 4 Classic
• Prestige: Yes
• Modpack Version world created in: 4.0.1
• Additional Content Installed: OptiFine_1.12.2_HD_U_E3

Client Information

• Modpack Version:
• Java Version: Java 1.8.0_211
• Launcher Used: ATLauncher
• Memory Allocated: 6144 MB
• Server/LAN/Single Player: Single Player
• Optifine Installed: OptiFine_1.12.2_HD_U_E3
• Shaders Enabled: NONE

[mklprudence]

Forgot to state the modpack version, the crash log came from 4.0.5, but the crashes have been occuring back in 4.0.3. IDK about versions before as I have not got into using Cyclic stuff back then