@abomma The error you are encountering is occurring in DITA-OT due to either : Issue with custom map DTD or Validation of Ditamap  You can open  Ditamap in the web editor and check if there is any validation error.If the issue persists download the map and attach it here or send it to us directly.-P...

@sschnelbach We are working on this request with a reference GUIDES-18087 -Pulkit

Any modification to the metadata of a topic will mark it as 'dirty' (*). Have you recently made any metadata changes to the topic or anything else that might affect it at the node level?-Pulkit N