HttpOnly cookie in SharePoint interrupts browser workflow creation

Question

This is not a question, but the solution I just opened. The problem was this: When I tried to create an approval workflow in the document library through a browser in a MOSS Enterprise installation, I received an "Unexpected error" message. Error output to browser, I received

Value cannot be null.
Parameter name: g at System.Guid..ctor (string g)
  at Microsoft.Office.Workflow.WrkAssocPage.AssociationOnLoad (EventArgs ea)
  ...

Magazines did not provide more useful information.

I found this page http://social.msdn.microsoft.com/forums/en-US/sharepointworkflow/thread/f84f0878-5c40-41fa-accc-9961cef93792/ , which has some promising solutions, but none of them worked I have.

The solution that worked for me was to disable the HTTPOnly cookies that I recently included in web.config using the string <httpCookies httpOnlyCookies = "true" />.

Answer 1

The code on the forms on these pages should be able to store data in cookies.

The solution is this: do not put httpOnlyCookies="true"web.config in your file if you want to use workflows.