How to produce warning message if columns/rows are added?

[smw10c]

I have a worksheet change event embedded in a workbook that a coworker uses for presentations. Every time they present, they add a column which throws everything off and then produces errors (started using named ranges but still haven't been able to prevent all of the errors). I want to have a warning error appear if they add a column or a row to stop them. Any advice?

[Keebellah]

How about protecting the worksheet?
Have you thought about that?

Another way but that will depend on your VBA knowledge is that you check is the number of columns changes that ne delete the active column

[Roel Jongman]

Can you post an example file and the code?
Based on this description it is impossible to provide a solution.

My initial idea is that if they add a column at every presentation there must be some logic behind that madness to do / demonstrate that action. So let them present of of a copy of your original file so their presentation does not interfere with your efforts.

having all kind of selfbuild warnings popup during a presentation can also be just as annoying as it is for you to have an added column in the file after a presentation.
Not every problem should be solved with more code.. Some applied logic, like using a copy of the original can prevent a lot of issues..