Server instantly closes when I start it

[red swallow]

I've been trying to open my server and play in it
but it insta closes and sends me to the hub
It worked 15 minutes ago, but I had to change the server version to the one I wanted to play on and since then it's been
immediately closing whenever I try and start it

idk what to do

[fierce thorn]

if you downgraded it it's because the world is still on a newer version so you can't start it
you need to delete / convert the world to use it again

[red swallow]

it works now