I've already fixed the issue. And I was wrong on the type of HVDC. But even a symmetrical monopole form a single circuit. If one cable is broken the whole system is out.

A bipolar HVDC is a single circuit, not two. Please fix all your HVDC tags that says circuit=2

Om du skal redigere landcover så må du setter deg inn i korleis relasjonar og multipolys virkar.

Well it breaks Openinframap using data on the lines itself. So please don't change it yet. It is also much harder to maintain as many people are not very good with relations and they can break easily. There is no need to delete the tag on the line itself IMO.

Deleting things and moving it to a relation is not a good idea. Not all data consumers suppor things and will cause issues.

Why did you delete the frequency and wikidata on the Sheltland HVDC cable?

If someone mapped a path there then it is clearly used.

We see this all the time in OSM where land owner try to force delete a path because it is "private property", completely ignoring the freedom to roam.