In C#, the "Object reference is required for the non-static field" error occurs when a static method attempts to access a non-static member without an instance of the class, as non-static members are tied to specific instances rather than being shared across the class like static members. This issue is illustrated by an example in which trying to update a form label from a static method causes the error, and three solutions are proposed: making the non-static member static, creating an instance of the class within the static method, or converting the static method into a non-static instance method. The text also highlights the usefulness of tools like Rollbar for real-time error tracking and management, which can significantly ease the debugging process and enhance confidence in deploying production code.