Whenever I load any world, the game crashes after the loading progress reaches 100%, before any gameplay is shown. The crash results in the Exit Code "-1073740791" with the message "This crash may be caused by an out-of-date graphics driver or conflicts with screen recording software. Please ensure your graphics driver is up-to-date and disable or uninstall any screen recording software in use."

I have no screen recording software and my drivers are up to date, this crash only occurs with this mod installed.

It looks like the version of "Fabric Permissions API" I shipped is too out of date for 1.21.4. Try installing the latest 0.3.3 manually and see if that resolves it. https://modrinth.com/mod/fabric-permissions-api/version/0.3.3

Yep, that fixed it!

Sorry I forgot to clarify the version.

fzzy_config-0.6.0+1.21.3 for fabric, loaded on 1.21.4

Java error messages don't really tell us much; I'll need a full log to diagnose anything. Also, Fzzy Config is a library, is there a mod you just added that needs it as a dependency?

I installed Fzzy Config for the mod Subtle Effects, but the crash occurs without that being installed as well.
And here is the crash log

Fixed with release 0.6.1+