Mythicmobs cancel entity drops if not installed

[Achent007]

Describe the bug When i hit any entity when i have at least one entity with a custom drop, i got this error on console : https://pastebin.com/2C6exmRV

To Reproduce Steps to reproduce the behavior:

1. Setup a custom drop on an entity without have mythicmobs installed
2. hit any entity
3. See error

Expected behavior Remove the error

Desktop (please complete the following information):

• OS: [Windows 11]
• PC Java Version [8 build 391]
• Server Version [purpurmc 1.20.1-2062]
• Plugin Version [3.2.8-b241]