The fit check now looks inside every package

Before your installation moves to a new platform build, it checks that every installed package has been prepared for that build and that the packages fit together — that they were all prepared against the same pieces. If they were not, the update is held rather than applied, because a package prepared against the wrong piece is quietly discarded at start-up and its pages come up empty.

That check was only comparing the main piece each package ships. It turns out most packages carry more than one. A package that builds on a small shared piece — the collaboration tools, the AI core, the map control — carries a copy of it, so the package works even when it is installed on its own. On the current package set, 19 of 37 packages carry a copy of a piece that some other package owns.

Those copies were never compared with each other, so two of them could disagree and nothing would notice. The result would be the failure the fit check exists to prevent, arriving anyway: your installation keeps whichever copy it loads first, and every page prepared against the other one is discarded.

The check now reads every copy inside every prepared package, not only the main piece. If one piece appears twice as two different builds, the update is held and the Updates settings tab names both packages, the piece, and the two versions that disagree.

Carrying the copy is deliberate and has not changed — removing it would break installing those packages on their own. What changed is that "the copies agree" is now something your installation confirms before it updates, instead of something the build pipeline happened to get right.