WP Fastest Cache is a popular caching plugin (add-on) for WordPress, and it works on Loopia’s hosting. However, some of its settings can cause your site to display Internal Server Error. This guide explains the cause – the plugin’s Gzip option – and how to remove the incompatible lines from your .htaccess file.
Cause: the Gzip option
The error is usually caused by enabling the Gzip option inside WP Fastest Cache. You do not need this option, because Loopia’s servers already have Gzip enabled.
When Gzip is enabled, WP Fastest Cache adds the following block to your .htaccess file, which stops the site from working:
# BEGIN GzipWpFastestCache AddType x-font/woff .woff AddType x-font/ttf .ttf AddOutputFilterByType DEFLATE image/svg+xml AddOutputFilterByType DEFLATE text/plain AddOutputFilterByType DEFLATE text/html AddOutputFilterByType DEFLATE text/xml AddOutputFilterByType DEFLATE text/css AddOutputFilterByType DEFLATE text/javascript AddOutputFilterByType DEFLATE application/xml AddOutputFilterByType DEFLATE application/xhtml+xml AddOutputFilterByType DEFLATE application/rss+xml AddOutputFilterByType DEFLATE application/javascript AddOutputFilterByType DEFLATE application/x-javascript AddOutputFilterByType DEFLATE application/x-font-ttf AddOutputFilterByType DEFLATE application/vnd.ms-fontobject AddOutputFilterByType DEFLATE font/opentype font/ttf font/eot font/otf # END GzipWpFastestCache
Solution: remove the lines via FTP
Connect to your account via FTP, open the .htaccess file in your site’s root and delete the block shown above. Save the file and upload it back to the server. The site will reappear.
The AddOutputFilterByType directive is no longer supported by Apache 2.4, which is why these lines must be removed.