You should have the latest version of Gravity Forms installed and running. This version of the add-on was tested with Gravity Forms 2.1.
Installation Instructions For The Gravity Forms Interface Add-on
Download the file to your desktop from the links provided in your purchase receipt or from your Account screen
In the WordPress Admin dashboard select Plugins->Add new
You should now see a screen with the list of plugins that are installed on your system. At the top left is a button labelled Upload Plugin. Click on it.
You should see a dialog box asking for the plugin file. Navigate to your desktop and choose the file you downloaded in the first step of this procedure then click the Open button at the bottom of the dialog box
You should now be back in the main Add plugin screen with the filename filled out. Just click the Install Now button.
If all goes well you will see a new screen with a link that says Activate Plugin. Click on it. That will complete the plugin installation process.
If you get a “directory already exists” error message, you will need to use FTP to upload the updated plugin to the folder that already exists. Check with your hosting provider for instructions on how to use FTP to upload files. Please make sure you “unzip” the plugin files before uploading them via FTP.