I am unable to use WP fastest cache

I put fastest cache code to htaccess (WP fastest cache code).

What happened?

1. My site always run to internal server error. I cannot enter into admin either.
2. When I deleted htacess file as desribed in Troubleshouting
3. Within 1 minute, the autorestore replaced the htaccess file, so I still could not enter to my site, receiving internal server error.
4. I deleted htaccess and deactivated BPS Pro from the wp_options table. Then I very rapidly changed auto-replace to 60 minutes.
5. I deleted the WP fastes cache code from htaccess.

Please give me a tested and good code for using WP fastes cache, or tell me which cache modul can be compatible with BPS Pro.

Thank you in advance

Zsolt