After an update of the URN service of the German National Library (DNB) at https://nbn-resolving.org, URNs of the type URN granular 2, recognisable by the component ‘/fragment/’, were no longer resolved, so that forwarding to the ULB presentation system no longer worked. The error was corrected by the DNB so that the service is available again without restrictions.
Granular URNs are used to persistently link a specific page of a work and remain valid even after the data has been moved to another server.
Work URNs and granular URN 1 (without the ‘/fragment/’ component) were not affected by the problem.