iPad Camera doesn't work in iMovie

Hi, I restored my iPad Mini (1st Gen, 64GB) to iOS 8.3, as I was having problems with crashing. I now have a problem with iMovie. The camera works fine in the camera app, just not in iMovie.

If I try to record from the camera directly in iMovie, then there are 2 possible outcomes:

1. The Camera Preview shows a blank grey screen, with buttons to switch to the front camera. It allows me to press record, but nothing is recorded. I cannot take still images, or switch to the front camera.
2. The Camera Preview does show, but it doesn't allow me to record anything, pressing the record button does nothing. I also can't switch to the front camera.

I have tried reinstalling the app, and clearing any saved movies, but it hasn't worked.

Thanks In Advance.