Font Test no display

Can anybody explain why the imported image does not display in Font Test after generation?

I have tried several ways of importing the image file, including doing nothing to it, validating it, changing the size (upem), but in all cases the Font Test only displays 3 radomly placed oblongs on the screen and these only show if I scroll down the screen and not at the top where I would expect the image to be.

Can you send a copy of your font directly to me? I’ll see if I can identify your problem.