http://www.zwsoft.com/forum/viewthread.php?tid=1832 generally, this problem can be fixed by re-install. I suggest you to try following methods for trouble shooting. 1. Try the latest version ZWCAD 2011. 2. Re-install ZWCAD as administrator. dwcollinsCAD 2011-08-15 03:22:45 http://www.zwsoft.com/forum/viewthread.php?tid=1832&pid=13691 I am getting the following error when trying to apply materials : "Error loading Materials Properties dialog" same type of error when trying to select a background : "Error loading Background Properties dialog" I have un-installed/re-installed the program, any ideas ? dwcollinsCAD 2011-07-25 23:07:41