1. The most common reason for the “Wrong Key” error is the outdated SNAP Helper plugin. Please make sure your SNAP Helper plugin is 1.5.5 or later. 1.4.X versions are no longer compatible with latest SNAP releases.
2. It also could be amount of memory allowed for PHP on your server. Please check and make sure it’s not 32M or less. You need at least 64M, but if you have other plugins 128M or even 256M is recommended.
3. Another possible problem is broken curl/sslcurl, please do [Test Connections and HTTPS/SSL] from Help/Support tab in the plugin and look for any possible connection errors.