floor plan window suddenly got blank screen,My steps
1. import background image;
2. sketch walls to plan graph;
3. draw rooms, except for a corridor space haven't enclosed.
4. place objects and ajust them,
suddenly plan window got blank, can do nothing in plan window,
3d view window still works.
the last operation i remember was that... I placed an object to that corridor space that I haven't enclosed to any rooms.
plz help~~~
