Magento 1.9.2.2 cannot create account and login on frontend

I'm using Firefox and I started to have a problem. I can't create new user in a Magento 1.9.2.2 in the frontend and also I can't login with a register user. In the backend I can create the user without problems.

This was not happening some time ago.

I tried these solutions and didn't work:

Add <?php echo $this->getBlockHtml('formkey') ?> to some files of my template.
Delete var/cache and var/session.
Change life cycle of the cookies.
Change domain name of the cookies.

Any idea? :(

Solution

If you cannot create a customer or login after applying patch SUPEE-6788 or upgrading to Magento 1.9.2.2 or later, this might be caused by missing form keys.

Make sure to add form keys to all of your (custom) template files:

In app/design/frontend/[package]/[theme]/template/customer/form/register.phtml and app/design/frontend/[package]/[theme]/template/persistent/customer/form/register.phtml

Add

<input type="hidden" name="form_key" value="<?php echo Mage::getSingleton('core/session')->getFormKey() ?>" />

after

<input type="hidden" name="error_url" value="<?php echo $this->getErrorUrl() ?>" />