ArchiCAD 11
MacOS X (10.5.6)
Sometimes, for no apparent reason, I'll be working away on a drawing that uses lines and fills of different colors (white background), and suddenly all my lines and fills change to black. I can get it to go back to the way it should be by closing the file and re-opening it, but does anyone know why this occurs, or how to prevent it?
Thanks in advance for your help.
Larry