how do i change difficulty?

[ItzMeHarris]

how do i change difficulty? When i type in /difficulty peacefull it says i have no permission.

[rosabel]

Try doing /difficulty hard, doing /save-all, and restarting your server. Best of luck to it working, though! If it doesn't, you can always install the Multiverse plugin and change the difficulty using commands from the plugin and that likely should work. The command is  /mv modify set difficulty hard <world>

If the problem persists and won't stop I've created a solution for this. I'll list the steps here. This can also do the trick if you don't want to go through the hassle of Multiverse.

Edit Server > Install Skript plugin > File Manager > Plugins > Skript > scripts > Create new file named "difficulty.sk" > Paste the code below this into that file > Click Save > Execute the command "/sk reload difficulty.sk" in game to put the code into effect. 
 

on load:
	set difficulty of world "world" to hard

Just be sure to set ` "world" ` to the name of your world inside the parenthesis. Case sensitive!