Understanding server crashes using console

Not enough storage.

Error before starting your server:

Error while your server is running:

To fix it, you can:
Follow a guide on know to fix it here.

No server.jar file.

To fix it, you can:
To fix this, you must rename your server jar file to server.jar, or change the startup in the Settings tab.

Corrupted world crash.

To fix it, you can either:
Delete your worlds and restart your server (Note: This will reset your world).
Switch back to the newer version the world was made in.

Corrupted .yml file.

To fix it, you can:
Follow this guide on how to correct your .yml file's syntax.