Ok well I think that you actually need a height map and a terrain map to be able to open the wbs in worldbuilder.
Using just a height map producing the following in the WBS file,
BeginPlot
x=1,y=122
BonusType=
TerrainType=TERRAIN_OCEAN
PlotType=3
EndPlot
BeginPlot
x=1,y=123
BonusType=
TerrainType=TERRAIN_OCEAN
PlotType=3
EndPlot
BeginPlot
x=2,y=0
BonusType=
TerrainType=NONE
PlotType=2
EndPlot
BeginPlot
x=2,y=1
BonusType=
TerrainType=NONE
PlotType=2
EndPlot
BeginPlot
x=2,y=2
BonusType=
TerrainType=TERRAIN_COAST
PlotType=3
I'm thinking you need to have a terrain map that's completely green for it to work in the Worldbuilder.
That's the problem. In the .pdf manual it says,
"Actually, only the first is required to generate a map. You can just select the heights map, andpress Cancel for the others."
This is not true. You need a height map, and a terrain map that is completely green for it to work.
EDIT: yes I've just tested this and that is the problem, my new map works but you need to have atleast a height BMP and a completely green terrain BMP fo it to work.