Zeldore

I also had the same problem and I this is how I solved it: Open "Settings" -> "Build, Execution, Deployment" -> "Gradle". In the "Gradle projects" section select your project. "Build and run using:" is set to "Gradle". Select "IntelliJ IDEA" instead. I don't know why this solves the problem and what consequences this may have (e.g., maybe you will have to manually run some gradle tasks each time you change forge version, etc), but this does allows you to use Hot Swap.

It is said that this event is fired only on the server side. Unfortunately, I can't use it, because I am developing a client-side only mod.

I need to run some code when held item is changed in some way (e.g., durability is changed or some other item is now held). Is there some event suitable for this? I know this could be done with PlayerTickEvent, but in this case I would have to detect changes myself.