Players running certain magic mods kept reporting purple smoke around a Skeleton's burning skull. Chasing it turned up something larger than one bad effect: the mod asks the game for things by name, and nine of those names are not in Valheim at all. Each one failed without a word, which is why an item promised since 1.4 had never once dropped and a whole attack had never made a sound.
Two things, both about the difference between the machine an action happens on and the machine that decides what it means. A Trol's fists were being handed the boss bonus on the host's machine, where the hit does not belong to the local player. And every player's own config file was being read as truth, in a game where everyone has to agree on the numbers.
v1.4.19 taught the Fenrir's forms to walk on other people's screens and said plainly that the attacks would need their own fix. This is it — along with a Fenrir who turned back into a human at every sunrise regardless of what the tier allowed.
A tester brought a second Skadi along, turned into Moder, and found that each of them saw themselves correctly and the other one full-sized. That is the whole class of bug this release is about: a form built around the local player, with the remote copy left to guess.
A tester noticed wood going missing. Building something your race is not allowed to build showed the refusal, stopped the building, and then charged you for it anyway — because Valheim takes the cost in a step that never heard about the refusal.
Plus a gamepad problem with the same shape: a Skadi who could barely build, because every piece she placed also cast a spell.
Five tester reports, and four of them turn out to be the same shape of bug: something the mod computes for everyone except the player it belongs to. The Trol's height existed on every screen but their own. The Fenrir's forms animated for everyone but the transformed player's onlookers. A truced mob took a hit personally and forgot about it one frame later.
Valheim 1.0 added fields to every shop item, and a September hotfix changed how the game reads a gamepad's left stick. Both landed on this mod: the faction merchants could not open a shop window at all, and the Drake could not fly. Plus the Fenrir running at twice the speed it advertises, which has been true for a long time and nobody had measured.
Valheim 1.0 added one extra value to the calls that put an item into a station, and changed how a mead barrel records what is in it. Neither is a large change. Between them they stopped every Bone Servant working, at every station in the game, and quietly took the Aswid's four-times fermentation away.
Alongside those: the radial menu, flight on a gamepad, and six fixes to the Sverm's colony.
Valheim has exactly one flight, and it is the debug-fly flag the developers use to move around their own game. The Aswid's bat has always flown on it. What nobody had read closely is what vanilla does with that flag: it treats the player as not really present. Six methods act on it, and between them they meant a bat could not be seen, heard, woken for, or hurt.
That, a night-only restriction that had never once been enforced, and Skadi's spells finally paying into a skill.
Three tester reports against the Bone Servant, all with the same shape: the servant was doing exactly what the code said, and the code said the wrong thing. Alongside those, an input gate that let abilities fire through the build menu, and a Sverm beehive cap that was configured but never actually read.