Support

Mandatory information about my setup:

Have I read the related troubleshooter articles above before posting (which pages?)? yes
Have I searched the tickets before posting? yes
Have I read the documentation before posting (which pages?)? yes
Joomla! version: 2.5.6
PHP version: 5.3.14
MySQL version: 5.0.95-community-log
Host: avalon.hr
Admin Tools version: 2.3.1

Description of my issue:
I have user name and password for protecting pre-load administrators page - work correct
I have set WAF. All option I have set as described in manual. I think work correct.
Next step, I try to create .htaccess, but there is problem:
When I save without creating .htaccess - it works.
If I try to save with creating .htaccess I get message:
500 Internal Server Error with message: Additionally, a 500 Internal Server Error error was encountered while trying to use an ErrorDocument to handle the request.

Please, can you help me?
Regards.

.htaccess maker after disabling all oprions and testing why I have problem I found next situation:
all options working very well and I can changing and creating .htaccess, and I'm very satisfied. Only 'Disable directory listings (recommended)' in Basic Security don't work at may side.
When I set that option to YES and pressing save with creating .htaccess automatically I get error message 500.

I didn't found answer in documentation why that option can be problem, and please, can you assume what can be wrong at my side.

Regards.

My provider told me that the option 'Disable directory listings' is in status ON at the server, and there is no need to adjust by using .htaccess.
Thanks for your support.