Kernrechtsfrage
Whether the cantonal court violated the duty to investigate by deciding without all administrative files.
Extrahierter Entscheid
The investigation principle was violated because not all relevant files had been transmitted, but the defect was not decisive for the outcome.
Extrahierte Begründung
A social insurance court must have all relevant files. Here three contested documents were missing. However, the MEDAS report available to the court already showed no decisive additional incapacity, so the omission could not change the result.