Same here. I have
An error occured: Piwik did not answer. Please check your entered Piwik URL
in the plugin home and
An error occured: Please check URL and auth token. You need at least view access to one site.
within the settings tab.
I have tried several things – turning off casheing, made a user and gave them view acccess and used their individual auth code, several variations of the URL just in case. No luck.