I assume you are talking about WED and not the engine. Just don't test your game in fullscreen but windowed mode (or try choosing different view drivers unter preferences (or similar)). There is an option to "Recreate Views" under the View tab, try it. You can simply click on "File" in the upper left WED corner and select your level from the previously loaded levels, this will recreate the views, too.
"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual