What if a supplier sends a broken file?

The import stops before anything changes when the file:

• is empty;
• is much smaller than last time (default: more than 50% smaller);
• would remove too many products (default: more than 30%).

You get a notice, and an email if alerts are on. Your stock is untouched. Each supplier's limits are on its Settings, under Rules and safety limits. If the file really is right, Import anyway on the supplier's page (in the workspace) lets it through once.