Hey Marko,
I have checked the debug.log and there was no error in there relating to Google PageSpeed or the W3TC plugin, the error is still there though after deauthorising and reauthorising. It still returns the error “Error : Not Found”
The site is publicly accessible, it’s https://www.danpye.com unless there is something I have done which would block access? I can’t imagine so though as I get analytics etc.
Thanks.