Unofficial Skyrim Special Edition Patch

Many people have reported incidents of NPCs in Solitude dying unseen, only finding out about the deaths by other related NPCs lamenting their passing afterwards. True enough, their final resting places appear in the Solitude crypts as well. This is known to happen even in vanilla Skyrim, despite reports of it inaccurately being attributed to heavy Solitude mods like Open Cities or city overhaul mods.

It has been determined that the most likely culprit is an improper unloading of exterior cell meshes: the region around Castle Dour, likely encompassing everything between (and including) the Solitude Marketplace and the Temple of the Divines, unloads ground meshes improperly when approaching the Blue Palace. Their mesh origin points may be in cells that end up outside the loaded exterior cell distance, but would still otherwise cover area inside a still-loaded exterior cell. NPCs in the area end up plummeting to their death on the terrain mesh below when the collision hulls for those meshes also unload.

The proposed fix is to use a series of trigger zones beneath the ground meshes in the affected regions, which will detect NPCs falling into them. They then will send them to their editor origin locations, which are all inside their respective houses. Presumably this will avert their death from falling damage.

Any Solitude NPCs already killed by this bug in a playthru would not be retroactively recoverable.