Hi Leon,
When sheets are grouped whatever text/values are typed into one sheet also
show in all the other sheets in the group. This also includes all the
formatting applied such as column widths, fonts, etc., so it's pretty handy.
[Group] shows in the title bar whenever any or all sheets are in group mode.
To undo group, right-click on any sheet label, and choose "Ungroup sheets".
It's pretty easy to put sheets in group mode by mistake just by clicking once
on the first sheet name, holding your shift key, then clicking the last sheet
name.

HTH
"Leon Brown" wrote:

Hello,

I have a spreadsheet which has [Group] in the title bar. I can't create
charts, can't run other tools. I can't figure out how it got there, nor how
to get rid of it. I have resaved, but still can't figure it out.

Any hints appreciated.

--LEon