Bug: Rings of Blood Magic location unavailable [SPOILERS]

[PVersusNP]

When starting the Rings of Blood Magic quest, it is possible for one of the rings' locations to be set to the Katariah, a ship that does not appear unless one decides to proceed through the Dark Brotherhood questline in favor of keeping it alive. This effectively blocks progression through the Castle Volkihar storyline in Dawnguard.

Is anyone else having this issue at the moment?

[Mephitic]

This is fixed by the Unofficial Skyrim Special Edition Patch.

The Katariah was erroneously flagged as a dungeon which could lead to several radiant quests choosing it as a target location and therefore requiring the full completion of the Dark Brotherhood quest line to retrieve the target object. (Bug #162)

[Zsrai]

It may just be that the location is on Solstheim. The marker won't show up in Skyrim because Solstheim is a separate world space. This is very likely the cause if you have the Unofficial Patch.