You need to enable groups for your selection.
Edit > grouping > suspend groups
or ALT + G
or find the icon on your toolbar or use the Control Box palette (which is useful for other reasons too), which has enable/suspend groups on it.
Erwin Edel, Project Lead, Leloup Architecten
www.leloup.nlArchiCAD 9-26NED FULL
Windows 10 Pro
Adobe Design Premium CS5