Currently, if GoreCore cannot retrieve an account UUID and there is no cache, it will log an error and return null. This will usually cause a NPE somewhere in the code.

The main cause is using a cracked client, but it also will crash if the computer is offline or Mojang's account system is down. GoreCore should generate a random, temporary UUID along with a warning message.

• Reform return type from UUID to AccountID, which contains both the UUID and whether it is temporary
• Put temporary UUIDs in cache, but also mark them as temporary
• Add command to remove temporary UUID by getting ID from online then replacing the old ID in cache & map

Generating temporary IDs and marking them, added command to change, but need to fix changing UUID messes up player data

Unfortunately, it's impossible/complicated to fix offline UUIDs.