Version Info

• Minecraft, 1.19.4
• Packed Up, packedup-1.0.28-forge-mc1.19.3.jar
• Core lib, supermartijn642corelib-1.1.7-forge-mc1.19.4.jar

Steps to Reproduce
load client
click create new world
crash

Crash report (~/logs/latest.log)
...

You're using an older version for 1.19.3. Install the updated version for 1.19.4.

Please remove the 1.19.4 tag from packedup-1.0.28-forge-mc1.19.3.jar as Curseforge sees it as the latest version when updating mods.

Sadly that's CurseForge issue. It seems this is an ongoing issue with a lot of other mods as well. Nothing I can do about that.

you can't go to the file and uncheck the 1.19.4 tag?