Bug linked with this comment by SolSpruce

Version: FabricCustomCursorMod-1.3.0.jar

Basically, if you edit your cursor file location to a location that only exists in a custom resource pack you've created (for example, ../gui/pointer-96.png), and then that resource pack gets disabled for any reason, the game will crash on load.
This is a major problem because resource packs can get disabled due to renaming them or updating various mods, and the user isn't really aware they've been disabled. Then, their game won't start up, and most folks don't know how to read the latest.log:

[17:30:50] [Render thread/ERROR]: Unhandled game exception
java.lang.IllegalArgumentException: input == null!
	at Not Enough Crashes deobfuscated stack trace.(1.18.1+build.14) ~[?:?]
	at javax.imageio.ImageIO.read(ImageIO.java:1358) ~[?:?]
	at fr.atesab.customcursormod.common.config.CursorConfig.readImage(CursorConfig.java:120) ~[FabricCustomCursorMod-1.3.0.jar:?]
	at fr.atesab.customcursormod.common.config.CursorConfig.allocate(CursorConfig.java:67) ~[FabricCustomCursorMod-1.3.0.jar:?]
	at fr.atesab.customcursormod.common.config.CursorConfig.getCursor(CursorConfig.java:85) ~[FabricCustomCursorMod-1.3.0.jar:?]
	...
[17:30:50] [Render thread/INFO]: Stopping!

I think your mod is trying to read an image that doesn't exist. You probably need a "try" block of code, or an if statement to avoid attempting to read the .png file that doesn't exist while the resource pack is disabled.
So, about that resource pack I created. Maybe someone else wants to use it too?
Preview Image of Custom Cursor
Resource Pack Download Link