Object under the cursor error

[ges]

I know this was discussed a little before, but I didn't see a fix.

Yes, I have hit the escape key.

After drawing much of my map, I suddenly started getting the "object under the cursor" message and could no longer place any objects.  The lightning bolt symbol appears and nothing works.

Any ideas why this happens and how to get past it?  I really hate to start from scratch on the map.

[ges]

well, I deleted one deep forest and then I could again place other objects.  Not sure why that worked.  It was the only deep forest object I had on the map.