What is a nice way to explain that performing a certain action will "break" a product? I have to explain to a customer that use of my product in an unauthorized manner will "break" the product, but I'd like to use a word that has the same meaning but more professional connotation while maintaining the robustness/integrity of my product in their eyes.
How about compromise?
To reduce in quality, value, or degree; weaken or lower.
I think this word has the advantage of implying any damage done would be due to user-error rather than a lack of "robustness" of the product.
We use the following phrases with our products:
The resolution of issues caused by using the product in a manner other than described will not be supported by our technical staff.
Using the product in a manner other than described is not recommended, as it may cause unexpected results.
EDIT: Oh, I noticed that you wanted a single word. You might try subvert or corrupt. Both of these terms would, I think, imply that the screw up was due to the user's interference, rather than the program itself.