When trying to name items from 1.13 or 1.14 with the /rename command, instead of naming the item the message [SimpleRename] You need to have an item in your hand shows up, this message also shows up in anvils and causes the player to exit the anvil GUI making repairing or naming crossbows or tridents impossible

I get this issue too, I found it when trying to rename one of the new 1.14 banner patterns. A fix for this would be great, it's a pretty big bug.

According to my tests I think I have fixed this bug in v11.2. Please reopen the issue if you still have problems.