I enchanted a Titanium Gold pickaxe while testing, then tried to stack more enchants on with an anvil. Upon putting the enchanted book into the anvil with the pickaxe (or vice versa), the game immediately crashed back to the launcher.

crash-2022-03-24_01.14.57-client.txt

Thanks for the crash log, I think I know where the issue is.

I am going to close this, as alpha+6 fixes this issue. If the crash persists, you are welcome to reopen this issue.