Apache rewrite rule forces download

Answer 1

Looks like an Apache config issue, of course I could be wrong. Have you checked httpd.conf for the following lines:

# Add index.php to your DirectoryIndex line:
DirectoryIndex index.html index.php

AddType text/html       php

Answer 2

I suppose that the MIME type application/x-httpd-php5 is not valid. I’ve tried it on my local machine and it caused the same behavior.

Have you tried application/x-httpd-php instead?