manage categories can't opened

[MGDevelopers]

hi

when i want to manage categories under catalog menu in version 1.9.2.2 

i face to this error:

Forbidden

You don't have permission to access /admin/catalog_category/index/key/ some key / on this server.

Additionally, a 403 Forbidden error was encountered while trying to use an Error Document to handle the request

i 'm website manager ,  is there any miss configuration in installing it to or any thing related to my host or changing in database

Any help will be appreciated.

[speerio]

Hello,

Check the file permissions, or the permissions on the server.

[MGDevelopers]

i checked it all folder permission on 755

and file permisson on 644.

what should i do next?