Maybe...
XL: "Cannot Shift Objects Off Sheet" Error Hiding Columns
http://support.microsoft.com/default.aspx?scid=kb;en-ca;211769
Remember to look for comments and merged cells.
And for objects that may not be displayed:
xl2003:
tools|options|view tab|Check Show All
xl2007:
Office button|excel options|advanced
Display options for this workbook|For objects|Show|check all
ctrl-6
Should do the same in any version.
Debra Dalgleish has a blog post, too:
http://blog.contextures.com/archives/2009/03/16/cannot-shift-objects-off-sheet-in-excel-2007/
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ps. You have a bug in your code. You'll see it if Sheet1 is not the
activesheet (if the code is in a general module)--or if Sheet1 is not the module
that owns the code.
This line should have the cells() qualified, too:
Sheet1.Range(Cells(1, 8), Cells(NbListClients + 1, 12)) = ListClients
either:
Sheet1.Range(sheet1.Cells(1, 8), sheet1.Cells(NbListClients + 1, 12)) _
= ListClients
or (I like):
with sheet1
.Range(.Cells(1, 8), .Cells(NbListClients + 1, 12)) = ListClients
end with
The leading dots means that that object (.range() or .cells()) belong to the
object in the previous with statement--in this case Sheet1.