I have users who are trying to access a K2 form via a link in SharePoint and they will sometimes get an access denied error when clickin on the link.  These users are in a security grop that was created in AS and then that group was assigned "contribute" permissions within SharePoint.  The problem seems to happen randomly as some of the users were able to access this form earlier this week but as of today they are not able to.  I have included a screenshot of the error the users are receiving.  I had also added them manually outside of the AD group and that seemed to work until today.  Any help would be greatly appreciated as these users need access to this form by the end of the day today.