I was working on a SharePoint 2010 designer workflow where we do have task form(InfoPath form). It was working fine and all of sudden we faced below issue when we click on the task to approve/reject.
“The form cannot be displayed in the browser because the use of session cookies has been disabled in the current browser settings. In order to load the form, session cookies must be allowed.”
as shown in the below image:
The message says it is due to cookie which is disabled in the browser. after enabling it, it was giving same error.
Finally we found it is due to HTTPOnlyCookies attribute which was set to true in web.Config file.
To solve above issue, Go to web.config file in your web front end servers and search for httpCookies tag and set HTTPOnlyCookies attribute to false. That’s all:-)
Prasanta Barik 