PROBLEM Invalid Referrer

[adminkg]

When "Edit Page" and click "Save Updates" I have:

Invalid Referer
-------
Invalid Referer: http://something.pl/Invalid Referer
-------------

Fresh instalation, GS - last, Edit page - "Welcome to GetSimple!"
One week was good. Now, something is wrong. Is hosting admin could change something in the server settings?

/admin/health-check.php
GetSimple
GetSimple Version 3.3.13
Latest version installed
GSLOGINSALT No
GSUSECUSTOMSALT No
Server Setup
PHP Version 5.6.13 - OK
cURL Module Installed - OK
GD Library Installed - OK
ZipArchive Installed - OK
SimpleXML Module Installed - OK
chmod chmod - OK
Apache Web Server Apache - OK
Apache Mod Rewrite Installed - OK
PHP disable_functions passthru,proc_close,proc_get_status,proc_nice,proc_open,proc_terminate,shell_exec,system,apache_note,apache_setenv,closelog,debugger_off,debugger_on,define_syslog_variables,openlog,syslog,popen,pclose,exec,ini_restore,symlink

For more information on the required modules, visit the requirements page.
Data File Integrity Check
/data/pages/index.xml XML Valid - OK
/data/other/404.xml XML Valid - OK
/data/other/authorization.xml XML Valid - OK
/data/other/components.xml XML Valid - OK
/data/other/pages.xml XML Valid - OK
/data/other/plugins.xml XML Valid - OK
/data/other/website.xml XML Valid - OK
/backups/users/admin.xml XML Valid - OK
Directory Permissions
File Name: /data/other/plugins.xml 0755 Writable - OK
/data/pages/ 0755 Writable - OK
/data/other/ 0755 Writable - OK
/data/other/logs/ 0755 Writable - OK
/data/thumbs/ 0755 Writable - OK
/data/uploads/ 0755 Writable - OK
/data/users/ 0755 Writable - OK
/data/cache/ 0755 Writable - OK
/backups/zip/ 0755 Writable - OK
/backups/pages/ 0755 Writable - OK
/backups/other/ 0755 Writable - OK
/backups/users/ 0755 Writable - OK
.htaccess Existence
/data/ Good 'Deny' file - OK
/data/uploads/ Good 'Allow' file - OK
/data/users/ Good 'Deny' file - OK
/data/cache/ Good 'Deny' file - OK
/data/thumbs/ Good 'Allow' file - OK
/data/pages/ Good 'Deny' file - OK
/plugins/ Good 'Deny' file - OK
/data/other/ Good 'Deny' file - OK
/data/other/logs/ Good 'Deny' file - OK
/theme/ No file - OK

P.S.
Hello everyone

[shawn_a]

Yeah changedata.php does referrer checking is there a reason your refferer might be messed up or wrong?

[adminkg]

Yeah changedata.php does referrer checking is there a reason your refferer might be messed up or wrong?

This is a Firefox guilty.

Plugin "RefControl" for Firefox. Off and now it works well.

So in memory of others.

Sorry.