I have looked at solutions to what seem to be somewhat similar problems but they don't seem to solve my problem.  A georeferenced raster layer loads into the correct location in relation to other layers, so CRS is obviously OK, but has this black background which I don't know how to remove.

[![enter image description here][1]][1]

Thanks for any help.

  [1]: https://i.sstatic.net/R8JdB.jpg