1. First I click "Add/Remove Height".
2. Type in any positive number to add.
3. Click "yes" to add it to the bottom of the map.
4. Click "Add/Remove Height" again.
5. Type in any negative number to subtract.
6. Click "no" to subtract from the top of the map.
After doing those steps, since I updated to the patch, the following error message comes up. I didn't used to have this problem. The reason I do it is to wipe a map clean on a random map so I can create a new map from scratch.
Thanks.

