Maybe MultiUserChatManager.insertService should be public or add an new api works like it.
In class org.jivesoftware.openfire.muc.MultiUserChatManager,
now there is an api registerMultiUserChatService
"
This is typically used if you have a custom MUC implementation that you
want to register with the manager.
"
, but now there is no api to add serviceID for custom MUC, so getMultiUserChatServiceID ALWAYS return null, so some apis such as removeMultiUserChatService, updateMultiUserChatService and etcs crashes.