I am having a similar issue. I created a form used it, shared it. All was fine and then when I went back to my forms it wasn't there. The link I shared still works, so collecting the data, just can't get to the design view to see responses. When I go to the link in the history view I get the same error "IT policy has disabled the collaboration feature". Given the form is currently collecting data I would prefer to get access rather than rebuild it and request everyone unergoes the survey a second time.