Not Acceptable additionally a 406 Not Acceptable error was encountered

I install version 7.8.2 , I can create accounts, contacts, opportinuties, quotes, etc with no problem.
When I try to save a PDF-Template (of a quote), I load first quote sample made a simple change (or no change) and save it, the next error appears:

"[b]Not Acceptable

An appropriate representation of the requested resource /crm/index.php could not be found on this server.

Additionally, a 406 Not Acceptable error was encountered while trying to use an ErrorDocument to handle the request[/b]."

I verified that index.php exist, change permision to that file to 755 but the problem continue.

What I can do to save the templates?

Please check the similar argument here Not Acceptable! Error