SDK bug or am I missing something?

I have two strange problems with Hammer. I worked a bit on the landscape and added some prop_static entities mostly stones, but also a vehicle, but the dont show in-game. More strangely a brush that I deleted is still there and wont go away. It's not there in the editor (not invisable either), but still it's in the map when I start it. I deleted the BSP file to make sure Im starting the right file. I dont get it - any idea?

I was obviously missing this:

Error: displacement found on a(n) func_detail entity - not supported (entity 209, brush 0)

what does it mean? how do I find the entity?

(googled it)

The error was that I changed a func_detail to a displacement without making un-entitying it again.