Unable to make changes to Level/World

[tgwaste]

How do you make changes to your level/world? After server restart it goes back to where it was when it was first setup.

I tried [teleporting to world] /sw set world level world [make changes] savelevel done

But that doesn't work and the savelevel command does not provide any output.

[tgwaste]

Heres the fix: "SkyWars.php" line 135 of 216 --62%-- col 19

is not instance of level
if(!$arena->level instanceof Level) {

should be is instance of level
if($arena->level instanceof Level) {