Describe the bug
After a few hours of no problems, the error java.lang.UnsupportedOperationException: The method xxxx is not supported for temporary players. is spammed to the console and the tps is rapidly dropping.
The methods are e.g. getUniqueId and getWorld

To Reproduce
Actually I don't know

Expected behavior
The issue should not appear at all

Version Info
v4.5.1-SNAPSHOT - Dump cannot be provided
We will try to update the version, but I'm not sure if this will fix the issue, as it persists for a few version. (as seen in SpigotMC Threads)

Is there an exploit known?