Describe the issue
After selectively disabling certain mods at a time, I found that the combination of the 3 mods (5 including libraries) below causes a crash, near the end of loading.

Game Log
https://gist.github.com/JawboTau/56bd183f7c4f4ca34e1bf7f8e19340a5

Screenshots

Basic Information (please complete the following information):

• OS: Windows 10
• FancyMenu Version 2.14.7
• Forge Version 36.3.34
• Minecraft Version 1.16.5
• Active Mods:
  • Dave's Potioneering,
  • FancyMenu,
  • GeckoLib,
  • Konkrete,
  • Optifine,

I also tried adding OptiForge, in hopes that it would fix the crash, but it does not.
All mods are the latest version compatible with 1.16.5 as of this time.

Upon further testing, this is not an issue with FancyMenu, but with Dave's Potioneering and Optifine.

https://fm.keksuccino.dev/en/wiki/general/verified/optifine-alternatives :)