I meet the same problem. Although I removed the plugin via FTP, the admin area still completely blank. And the w3tc folder can not be removed. How can I completely remove them?
It break my sites when I am not logged, I think it is just becuase you have chosen a option “Don’t cacha logged user”. But now, my problem is I can’t get into Admin pages. All pages in admin dictionary can’t be visited , it just show a blank page……So, I have to reInstall my site with all
files and database, it is terribly suffering me. I hope it can work after reinstalling
