In Internet Explorer 11, why do I get an "Access is Denied" error when trying to log into Customer Portal embedded in an iFrame?
Customer Portal 2, Customer Portal 3
In IE11, third party cookies are blocked by default. With PTA enabled, this error occurs everytime because the cookie that is normally set with PTA can't be created. Instead, an "Access is Denied" error is thrown.
To enable third party cookies, go to Options > Privacy > Advanced. In there, click "Override automatic cookie handling" checkbox. Make sure the radio button "Third-party Cookies" is set to "Accept" and click OK.