Mall kiosk with a Windows error. Graceful handling of errors is everyone’s job. A poorly handled error can pull the user down into the lower layers of abstraction, destroying the user experience.
Handle errors gracefully, either hiding them, or displaying them as an integrated part of the user experience.
Special integrated error pages or messages go a long way to put the user at ease when an error occurs. It says: “we knew this could happen - don’t panic." This would include user error, coding error, and even OS and network errors where possible.
Assume everything will break - then work up from there.