See my previous comment

Ok Dear friend I just installed OSSN v4.1 and log out error persists : "The action you Requested is invalid "...I did right click on log out option and showed me this link : http://localhost/ossn/action/admin/logout?ossn_ts=1459960978&;ossn_token=2df169919f00a54fc6e40e4008224719
Please help me. Sorry for inconvinences. Thanks

I am sorry for my last wrong comment, we can not reproduce issue without enough knowledge ,
Did you tried to install on some other local computer?

Dear friend, I am trying to install OSSN v4.1 and I get the error during installation "MOD_REWRITE IS REQUERID" , which is wrong , because phpinfo ( ) show me that if it is.

Try to enable display errors in administrator basic settings , and try to logout again and see if there is something in error_log.

Yes, there is the .htaccess file in root of ossn files.

on xampp the mod_rewrite is enabled by defafult, make sure there is .htaccess file in root of ossn files

Dear friend, sorry for the wrong way to locate the screenshot, but I am using xampp 1.8.2, and phpinfo() give me the following configuration, where you can see that MOD_REWRITE is active. Thanks for advance.

Configuration
apache2handler
Apache Version Apache/2.4.17 (Win32) OpenSSL/1.0.2d PHP/5.5.30
Apache API Version 20120211
Server Administrator postmaster@localhost
Hostname:Port localhost:80
Max Requests Per Child: 0 - Keep Alive: on - Max Per Connection: 100
Timeouts Connection: 300 - Keep-Alive: 5
Virtual Server No
Server Root C:/xampp/apache
Loaded Modules core mod_win32 mpm_winnt http_core mod_so mod_access_compat mod_actions mod_alias mod_allowmethods mod_asis mod_auth_basic mod_authn_core mod_authn_file mod_authz_core mod_authz_groupfile mod_authz_host mod_authz_user mod_autoindex mod_cgi mod_dav_lock mod_dir mod_env mod_filter mod_headers mod_include mod_info mod_isapi mod_log_config mod_cache_disk mod_mime mod_negotiation mod_proxy mod_proxy_ajp mod_rewrite mod_setenvif mod_socache_shmcb mod_ssl mod_status mod_version mod_php5

The screenshot you provided is avaialble on to you , its localhost , we can't access the screenshot.

If you are using wampp see : http://forum.wampserver.com/read.php?2,30758,30767

First of all thank you for your attention. I don't have domain.com yet but I'm doing the tests locally on my PC on Windows 7 and Apache Server localhost. I just installed OSSN v 4.1 , and validation page tells me I must have activated the MOD_REWRITE, however I have already activated as you can see in the screen shot attached here. Please tell me that 's what this probably doing it wrong.