"JE McGimpsey" wrote:
How is trigger_area defined? Do you have protection set in std_number?

The names "std_number" and "dd_opertype" are single cells and "trigger_area"
is the name of a range of 5 cells. This is not the problem, however, since
the error also occurs if I provide either cell in the range individually.

Does Range("std_number") get set to whatever "xxx" is if you leave out
the "trigger_area" line?

It does, yes. The idea is that if the value in "std_number" is changed it
causes "dd_opertype" to update followed by the cells in "trigger_area" which
in turn update each other. A cascade, if you will. The funny thing is, that
it appears that whenever it is "trigger_area" (or any individual cell
therein) that triggers the event handler, I seem to get the error trying to
update any random cell in the workbook (not just the same sheet).

Due to time constraints I redid the entire section of the workbook with VBA
dropdowns (MSForms.ComboBox) instead of validation lists - but the original
solution was absolutely bloody elegant (well, just more scalable, really) and
I would have loved getting it to work. Still would.

- Thomas