Ok so they said that it was another mod by the name of Simple Generators, I've removed the mod as I can't contact the mod author as they have a glitched github page and comments disabled. It worked in the end, thank you to everyone in this thread, I appreciate it.
I haven't made a working mod since 1.12, but I'm starting a new one for 1.16.5 and I'd like it to support the Curios API. I've gotten that working, but I realized that in order to register a Curios slot, I need to reference the Curios API SlotTypeMessage class. I was hoping I could make Curios support optional, i.e. register the slot if the Curios mod is installed, or just gracefully ignore it if not, but if I'm referencing SlotTypeMessage and someone installs my mod without including Curios, won't that just crash? Is there something special I need to do to make the support optional? Or am I totally misunderstanding how dependencies are handled and worrying about crashes that won't happen after all?
I never had forge before, I am a first-time-installer and installed it, nevest version and still experience it.
Changed attack key to LeftCtrl key, not mouse button. How can I fix that there?
No attack problems in Minecraft Vanilla version with attack key set to LeftCtrl.