Removed a cliff, still a shadow?

At first I thought it was a boundary, but in this picture I have demonstrated the difference between the leftover shadow and a boundary.



I'm doing the terrain for a friends map, but the previous terrainer (terrain'eer?) screwed something up pretty bad. Not only are there blotches of shadow all over from where there used to be cliffs, but the sea/ground level is much different than the default, apparently, which is giving me problems with terrain hugging the end of the map.

Also, when flattening the cliffs to the level of the map, I couldn't just mouse over them with "Same level" (when starting on a tile of the level I wanted, of course). It stuck, and I had to raise and lower everything manually to flatten it. Possibly related?

I'm also told that the old terrain'eer has somehow locked water under the map, which could also be related, as the cliffs that left their shadow were also hugging water at the time.

Any ideas?

See if "File>Calculate Shadows and Save Map" does anything.

Oh :x. All these years on world edit and I've never seen that option.

Worked great, thanks.