Comment by larkost

Having been next to the people working with the FDA at one point, they do tend to give a lot of feedback, especially when they don't like something. And there were a lot of hoops to jump though where the feedback was "you are on track" for a while before the actual official approval of that step came through.

Very likely all of the core approvals were done, and they were just waiting on things like approval of software testing methodology (yes, they have to approve your software testing system), or something of the like.