All of a sudden I seem to be unable to ungroup a set of objects which have been grouped previously, either by me, or as a symbol.



Also cannot group a set of objects which I select when in the unlocked mode.



What am I doing wrong? Is it an issue with layers? I don't remember having this issue before.



Thanks.

It sounds like you have Unlock checked (the icon with an open padlock on it).  This state disables grouping across the whole document and allows you to edit the individual objects that make up groups and symbols.

Uncheck Unlock and you should be fine.

Kind regards,
Rob Robinson
Stardraw.com

No, because when I uncheck the padlock, clicking on an element of a group selects the whole group, but the group icon goes gray, and I am unable to ungroup it.



BTW, this seems to only happen with symbols, whether mine or pre-drawn. Objects I draw such as shapes respond normally to group/ungroup.



Thanks.

This is normal behaviour.  A symbol is not a group and cannot be ungrouped.  A symbol always behaves as a single entity except when Unlock is checked.

Only groups can be ungrouped.

Kind regards,
Rob Robinson
Stardraw.com

Thanks for the clarification, Rob.