Game version: 1.21.1 Neoforge-21.1.169
Mod wersion: 4.7.5.1

When I start the game, it sometimes freezes during the 'Minecraft Progress' phase,such as:

but it doesn't crash and there won't be any crash logs.When I started the game again,"options.txt"has been modified, especially the resourcepacks settings and keyboard settings have been reset.I can confirm that is the problem caused by this mod, because the problem no longer occurs after it is disabled.

Because there are no crash logs, there are only client logs.
https://mclo.gs/IHYtA5y

It's not GeckoLib.

Your modpack is an absolute trainwreck that is dying the moment it starts.

The problem was solved after installing ModernFix mod.
Laughing at a person CANNOT solve it.