therockisnow on "W3 Total Cache Error: Files and directories could not be automatically created t"

Dear Sirs,
Great plug in. I am just having problems installing onto my site.
The above error appears and after I follow the instructions to change the .htaccess file, no difference results. I am left with the error and the plug in does not install properly to start working.
Your help would be appreciated.

https://wordpress.org/plugins/w3-total-cache/