I am also having similar problems. I had originally uploaded the plugin with no issues. It just wasn’t working for me the way I wanted, so I ended up uninstalling it.
After uninstalling it, I kept having little issues with the site and finally noticed that there was a “dropin” plugin that was placed in the wp-content folder instead of in the plugin folder. I found out that it was part of the WP Super Cache plugin so I removed it via FTP.
Still continued having issues with caching and various items on our site not working properly. Through investigating I found that the same “dropin” plugin was back in the wp-content folder….strange.
I was advised to try and install the WP Super Cache again and then uninstall, hoping that when it did the uninstall this time, it would actually uninstall properly and pull all files with it that it was supposed. to.
Well, that was the biggest mistake ever! Now, I am like you and I cannot access my site and if I leave it as is, it is displaying my DB info and passwords, etc. I have restricted the site until a solution can be found.
I pray that someone monitors this post and we can get our situations fixed quickly! I have put a years worth of work into this site and am not ready to see it go down in flames because of a faulty plugin.
PLEASE HELP!
Thank you.