Hello,
I'd like to hop in on this as I'm getting the same error, but only when I try to use SSL. I recently decided to make my installation a bit more secure. Without SSL, roundcube (latest stable verion) works like a charm. However, when using SSL/https, I get an 500 Internal Server Error (Apache 2.4.10 on Debian Linux).
Uncommenting the Option in .htaccess does not help, I get the same error with the next lines, RewriteEngine, RewriteRule and so on.
Any ideas?
Thanks in Advance!