Form would not save

Is this when you submit a form or when you try and save a form in the Form Editor?

This sounds like it could be a PHP memory issue. I would suggest increasing your available PHP memory. If it works on really short forms, but quits working on longer forms that is because the AJAX is unable to complete because there isn't enough PHP memory. A lot of shared hosts default to a very low amount of PHP memory but it can be increased.

Here is an article on how to increase your available PHP memory:

http://www.nerdgrind.com/increase-wordpress-and-php-memory-limit/

@gfgirl Your issue is the same as @joethoron's. It's a MOD_SECURITY issue. Your MOD_SECURITY settings are blocking the AJAX request because it thinks it's a malicious attack. See this forum post, it outlines the fix and you may need to get in touch with your web host to implement it:

http://www.gravityhelp.com/forums/topic/forms-not-updating-after-being-saved#post-10305

@guevara If your issue is indeed the MOD_SECURITY issue the only solution is the only one you approached your host about. That is the only solution. If MOD_SECURITY is blocking the ajax request to that file, there is nothing we can do to resolve that. It's a web server firewall issue.

Your host is being overly paranoid. Plenty of users on the forum have had the same issue and updated their MOD_SECURITY settings to whitelist that file. They don't whitelist your entire server, just that single file. We have code in place on our end to prevent injection and malicious attacks using that file.

So whitelisting that file is not going to open up your site to hacks. But not whitelisting that file means Gravity Forms isn't going to work because the AJAX can't function properly.