when I sort it tells me to select a single cell, even though I did

[boombox]

Is this a glich? I'll select a single cell, click the sort button and I get
an error message. If I try to sort by a different column and then come back
to the one I want to sort, sometimes that works. But I very clearly only
have one cell selected. is this a bug?

 

[Bob Umlas]

Is it a merged cell?

 

[boombox]

No, it's just a regular cell. Nothing special about it, sometimes it's blank
and sometimes not, but it doesn't seem to matter. I can click a cell with a
value and one with out, and I'll still get the message. I can try another
cell in a nother column that has the same properties (filled or unfilled) and
it will work, come back to the column and it does work. This happens when
the values are numbers, letters, email addresses, etc. Sometimes it will
work and sometimes I get the error message, often with the very same cell.