Does anyone remember what to do when you open a pre-SDK map with a SDK mapper, and there are no tiles on it?
I remember there was a very easy solution, like saving with an additional version of mapper or adding some file into the mapper directory before saving. I even had it in my instruction on converting old maps on the old forum, but I can't recall what it was.
At the moment I'm using these sequence of mappers (if you are starting from a Fallout 2 map):
Mapper 1 by Dims -> Mapper 1.4.4 -> Mapper 1.17.2 -> Mapper 1.22.5 -> current SDK mapper.