My server randomly reset for no reason and I can't figure out why and what I can do to fix it

[cruelcrow]

Does anyone know what happened and how I can fix it?

[MrTibo]

Have you changed the "Level name" setting in the Settings tab by any chance? This is something people often do not knowing what the setting is actually for. The default value is "world", you can check the setting and your file manager to check if you still have your world. If you didn't mean to change the setting, you can simply set it back to world and restart the server

[cruelcrow]

Thanks after I did this it worked.