1" = 5 feet = 1 grid square.

Set your worries aside for a few days. Nothing is worth ruining Christmas over.

Just checking that you aren't importing the image as an image, and not a symbol.

Check that you haven't called the one that's missing exactly the same name as one of the existing symbols.

Remy just suggested - double check that it really is a png image, and that the length of the filename doesn't exceed 32 characters.

Filter->Mathematical->Span...

You're welcome :)

If you need more detail about it Remy wrote a FAQ on it here:

https://forum.profantasy.com/discussion/comment/99096/#Comment_99096