I'm trying to set the rowsource of a combobox when the drop down
button is clicked. It looks to be working fine, then I get an error
message from Excel saying that it has encountered a problem and must
shut down.

I stepped through the code with the debug feature and there is
definitely something wrong, but I've not been able to figure it out.
This is the code.

Private Sub ComboBox6_DropButtonClick()
ComboBox6.RowSource = "h_outermagnetbore"
End Sub

h_outermagnetbore is a range

When I click on the drop button, the selections are there, but then
the error statement comes up immediately and I must shut down Excel. I
can probably figure out some other way, but it seems like this should
work. Can anyone tell me why it won't work?

Thanks,
Greg