I built a short and simple procedure on my PC, tested it, converted it to an
xla, and made a button. I installed this button on a couple of colleagues'
PCs.

On only one PC, when the button is pressed, about a third of the macro runs,
then the debug window shows, saying the code has been interrupted (as if I
had pressed "Ctrl+Break"). If I hit "Continue", it then happily runs the
rest of the code as if no problem ever existed.

Do you know why, on one PC, Excel is acting as if I had pressed "Ctrl +
Break"?

thanks in advance
Daniel