http://bugs.winehq.org/show_bug.cgi?id=22588
--- Comment #31 from Florian florian@fkoeberle.de 2010-07-03 13:17:59 --- I found out why it started to work for me since my initial try with the OffscreenRenderingMode=backbuffer setting. It looks like the Terrain editor remembers which layer you had active. It stores the setting in: HKEY_CURRENT_USER/Software/Blizzard Entertainment/Starcraft II Editor beta/Preferences/TerrainActiveLayer
If this setting is 0 (= Terrain Layer) then the editor freezes at start. If it's 1 the terrain editor starts up fine. When you choose then the terrain layer via menu the editor crashes.