Minecraft: 1.21.8, modmenu: 15.0.0-beta.3, fabric loader: 0.17.2, fabric api: 0.132.0+1.21.8
The only other mods I have are my mod (blockhighlight_fx), modmenu, and fabric API
Here is the crash log: 4X4Sql3.txt

I'm not exactly sure what caused this, but in my fabric.mod.json file I have a path to an icon.png file nested inside the resources folder. When I opened the mod menu, the game instantly crashed. The only weird thing I can think of is that the image I used was a webp that I converted to a png, so maybe it didn't convert right and caused this?