It’s because the plugin has been pakcaged incorrectly I think.
Download the plug-in here https://downloads.www.ads-software.com/plugin/wp2grav.zip
Un-zip the plugin on your computer you’ll see a folder called WP2Grav
Inside that, there is another folder called WP2Grav. This is where the plugin files are.
Either FTP the 2nd WP2Grav folder to the wp-content/plugins folder on your server.
OR
Create a new zip file from the 2nd WP2Grav folder and upload that file from the Add Plugin page in your WordPress dashboard.
you’ll now have to activate it and it should work normally now
