Sandbox settings will not save.

[lean cairn]

Im trying to chance zombie respawn and some other settings in my gportal hosted server but when I try to chance the setting they will only save for the moment the server is on and when I restart the server to update mods the config will come back to whatever it was before, I could change the settings before but now I cant, I even used the /save command to make sure they save.

[alpine hinge]

If you have any mods enabled, some of them can cause such issues

To try and fix this, go to the save folder of the server and delete the "map_sand.bin" file after backing it up