How to Disable the Nether

First Step

Login to your Wepwawet Control Panel

Second Step

Select your Server

Third Step

Make sure to Turn OFF the Server

Fourth Step

Under the General Section, Click the Files tab

Fifth Step

After that, Click on the server.properties file and go to the line that says allow-nether=true and change it to allow-nether=false and then click one Save Changes.

Sixth Step

After that, Head over to General tab, Click on Console and Start the server.