Hi pasqualerose
I can confirm this plugin caused the same issues in a friend's website using WordPress version 4.2.3 and plugin version 1.4.4. After deactivating and removing this plugin the website did return the normal operation thankfully. However after changing to php version 5.5 in GoDaddy hosting panel and activating again it appears to work ok but just slows the site down.
For anyone else experiencing issues Google wordpress wp super cache overloaded and also look at the web host you are using. My friend uses GoDaddy, it always has problems with slowness however changing PHP version to 5.5 and clicking Current then Save also helped a lot.