On restarting a headless server with an existing world no world is retrieved from the game manifest

What you were trying to do

Test something unrelated, by which I ended up restarting a headless server.

What actually happened

The restart failed to bring the game server back up

How to reproduce

Start a headless server with any config (like just starting the headless run config in IntelliJ)
Stop the server (can potentially skip steps 1 & 2 if you can reproduce with an existing save)
Start the server again

On InitialiseWorld line 100 the failure occurs. The gameManifest loads but has no entries in its worlds list

Log details and game version

Latest develop

16:48:21.601 [main] INFO  o.t.w.c.b.ExtraBlockDataManager - Extra data slots registered:
16:48:21.604 [main] ERROR o.terasology.engine.TerasologyEngine - Uncaught exception, attempting clean game shutdown
java.lang.NullPointerException: null
    at org.terasology.engine.modes.loadProcesses.InitialiseWorld.step(InitialiseWorld.java:101)
    at org.terasology.engine.modes.StateLoading.update(StateLoading.java:243)
    at org.terasology.engine.TerasologyEngine.tick(TerasologyEngine.java:458)
    at org.terasology.engine.TerasologyEngine.mainLoop(TerasologyEngine.java:421)
    at org.terasology.engine.TerasologyEngine.run(TerasologyEngine.java:397)
    at org.terasology.engine.Terasology.main(Terasology.java:145)
16:48:21.604 [main] INFO  o.terasology.engine.TerasologyEngine - Shutting down Terasology...

Theory

Either the game isn't correctly saving the world in the first place or the game manifest isn't correctly figuring out where the actual world went so it can list it. Might relate to some of the multi-world changes, although that was a few months ago. Since it works fine the first time you launch a headless server maybe we somehow missed it this long.

Also works partially with a client/server hosting a fresh game, exiting, then re-hosting. No crash, although when I tried it the client loaded into a black screen with no world visible (did have toolbar items etc)

MovingBlocks / Terasology