There is a strange bug that causes, when pairing ModernFix with any mod that helps to sort inventories to cause some items to be placed in the user's hand, practically disabling the ability to sort properly.

Demostration:

Variables to consider:

• Only affects specific items such as weapons and armor.
• ModernFix MUST be installed on both server and client (removing it from one of the 2 solves the bug).
• Bug does not appear when playing on singleplayer
• Mods tested: Inventory Profiles Next; Inventory Tweaks Renewed; & Inventory Profiles
• Minecraft Version: 1.16.5 (Forge 36.2.34)
• ModernFix Version: Latest version (5.0.2)

The bug is present since ModernFix 1.16.1, according to my observations.

Hmm, weird one. I'm having trouble reproducing it locally (with just ModernFix and Inventory Tweaks Renewed installed, no other mods). Does it happen if mixin.perf.nbt_memory_usage is disabled in the config? Are you able to reproduce it with no other mods installed except these two?

Can I have a look at the crash report?

• Does it happen if mixin.perf.nbt_memory_usage is disabled in the config?:
  No it doesn´t. Disabled on both sides

• Are you able to reproduce it with no other mods installed except these two?:
  Yes. Now Minecraft even crashes sometimes

For now, I will keep mixin.perf.nbt_memory_usage as it is, since it technically solves the problem

crash-2023-06-19_20.47.19-client.txt

This crash occurs when you press the sorting button several times without removing the item from your pointer.
(Only happened to me when I enabled mixin.perf.nbt_memory_usage, and the above condition is met.)

Can you try the latest 1.16 dev build from the README with mixin.perf.nbt_memory_usage re-enabled? I think I have probably fixed the issue.

The development version is working properly, thank you for your time.

Great, thank you for your patience. This is now fixed in 5.0.4.