The doctrine of operational risk has long been a central element of German labor law. It concerns situations in which employees are unable to perform their work due to business disruptions beyond the control of either party. For over a hundred years, the Federal Labor Court has determined the employer's obligation to continue wage payments not only on the basis of the Civil Code but also by reference to this doctrine. The author presents a comprehensive reassessment, the first since 2001. This new inquiry is essential, since the Court has recently elaborated and refined the doctrine in its rulings on pandemic-related closures, and because the modernization of the law of obligations introduced § 615 sentence 3 and § 313 Civil Code, thereby reshaping the normative framework. The analysis demonstrates that the Federal Labor Court has exceeded the constitutional limits of judicial lawmaking by ignoring the doctrine of frustration of contract (§ 313 Civil Code) when distributing operational risks. The author confines himself to making this constitutional violation visible and to encouraging the Court to revise its jurisprudence. Economic or comparative perspectives are deliberately excluded.