If you get the “Wrong API key” error message while adding a new site, you will need  to re-enter the API key on your WP Remote plugin.

In order to do this you will need to deactive and then reactive the WP Remote plugin. The API box will be shown when you reactive the plugin and you can re-enter the API key as shown on on the WP Remote site.

API key

The easiest way to make sure you get the correct API key is to open your site in another browser window and then copy and paste the API key from the WP Remote screen to the WP Remote plugin in your site.