I'm not one of the devs so I don't know for sure, but my (non-game) developer instincts are crying out "data indexing problem."  It's reminding me of issues I used to have with older database formats, with the file size growing quickly and performance taking a nose dive. It does kind of make sense to me, if players are digging up resources (spawning new entities) and exploring to new chunks that were either not fully defined or not defined at all when the map was created.  The server would probably append that data to the end of the game file, or the end of certain blocks of data.  Over time, the indices can get muddled, and lookup operations in the code get slower and slower.  It can even result in corrupted data.  And the problem does happen on local single-player games as well, it just takes a whole lot longer to get that bad. IF that's the case, then fixing it for the long term will be a pain.  I don't envy them on that job.  However, maybe something could be added to server options to take a map offline and rebuild the indices, on demand or on a schedule, that could ease the pain until a full fix is complete. And just for the sake of saying it again:  I don't know that is the problem, really.  This is just reminding me of issues I've faced with older business software I've built.