Unable to save JEvents Config

This is possibly because you are running php 5.3.x+ and the HTML form being submitted has more than 1000 elements in it.  The JEvents config can exceed this number. 

From PHP 5.3 onwards it has a default limit of 1000 on form input variables and therefore needs increasing.

Before editing your .htaccess file, ONLY edit it through FTP or a Control Panel, NOT your site.

To resolve this please add this to the bottom of your .htaccess file
[codep]# JEvents form submission issue
php_value max_input_vars 3000[/codep]

If the above does not cause an error on your site but the problem still persists you may have php suhosin install on your server so try:
[codep]php_value suhosin.post.max_vars = 3000
php_value request.max_vars 3000[/codep]

If that causes an error on your site then add this to your php.ini file
[codep]max_input_vars 3000[/codep]

If that does not work then you may have php suhosin installed on the server so try:
[codep]suhosin.post.max_vars : 3000
suhosin.request.max_vars : 3000[/codep]

If you need more assistance with these settings please contact your hosting company