When a server is started up and a world folder already exists with ONLY a data packs folder inside, and inside a data pack (specifically tested using the CavesAndCliffsPreview data pack from pre4), the server fails to start and causes an error: Encountered an unexpected exception z: Exception initializing level. After this initial crash, some other files are created in the world folder and starting the server again seems to be fine... but that shouldn't be happening.

To reproduce:

1. Create server.properties with a world folder name set
2. Create the world folder manually
3. Create a datapacks folder manually
4. Insert the CavesAndCliffsPreview data pack into the datapacks folder (Should look like: SERVER_FOLDER\world_name\datapacks\CavesAndCliffsPreview.zip)
5. Start server
6. Encountered an unexpected exception z: Exception initializing level
7. Run server again
8. Runs fine (I think)
   OR
9. Download .zip file provided ("Raw server folder without jar.zip") which has everything except the 1.17pre4 server.jar
10. Run server
11. See crash
12. Run server again
13. Runs fine (I think)

What should happen:
Repeat steps 1-5
Server starts up and loads data pack just fine first time.