Yes, the German Störung is really tricky, because it is so clear and simple in German, but there is just no single term for it in English. In this context I would go for error, otherwise there are many helpful terms for a rather technical context: breakdown, bug, disruption, disturbance, failure, fault, incident, interference, interruption, malfunction.... I've done a number of technical and IT-related translations where the term kept coming up and I was always struggling until I realised that there is just no single handy term for that word in English and it always depends on the context. (In the IT-context for instance Störungsmanagement is Incident Management and not fault management or something else.)