Fixes exploits causing duping and possible server crashes from version 3.14.1.1 (an update is necessary if you're using that version) - some blocks when opening panel blocks will break panels allowing players to grab items in GUI. - Clicking a stationary Hotbar item to open a panel while a panel is open will allow players to grab GUI items. - Opening a panel block with a panel item in your hand has the chance to crash the server (of course the GUI breaking and you can get the items too) - Using /cp <panel> or custom commands while a panel was already open would allow players to take items from GUI
Internal Cause: There was missing code that would normally check to make sure a panel wasn't already open before opening the next panel. If there was a panel already opened, it would need to internally ensure the first panel is the one being closed.
This version can be exploited (item duplication), use v3.14.1.3 instead!