W3 Total Cache – 500 internal server error solution (kind of)

http://wordpress.org/support/topic/plugin-w3-total-cache-htaccess-file?replies=25
http://wordpress.org/support/topic/plugin-w3-total-cache-500-internal-server-error?replies=40
http://wordpress.org/support/topic/plugin-w3-total-cache-500-internal-server-error-2?replies=13
http://wordpress.org/support/topic/w3-total-cache-500-internal-server-error?replies=7

After receiving a lot of errors and playing around with .htaccess file, I found the cause of this annoying problem. It’s those 3 lines below that are always causing our websites to get the “500 Internal Server Error” issue.

<IfModule mod_headers.c>
        Header append Vary User-Agent env=!dont-vary
    </IfModule>

I am able to fully use W3 Total Cache now, if you are receiving “500 Error” whilst changing settings in W3 Total Cache, then go to your .htaccess file and find those annoying 3 lines, remove them, then save .htaccess file.

Now if you want to change some other settings, you will most likely get “505 error” again, if you do, go to your .htaccess file, but before you do, make sure you refresh the page where it’s in so that you will be able to see the newly updated .htaccess, not the old one. Anyway, open it up and delete those 3 lines again, save… Then repeat! You’re welcome! 😀

http://wordpress.org/extend/plugins/w3-total-cache/