A page no longer settles for the generic view

Opening an item builds its page from the type it belongs to. The platform waits for that type to report a finished state — built, or failed to build — before it decides which views the page gets. That decision is made once and kept for as long as the page's engine stays warm.

Sometimes the wait ended early, on a snapshot from before the build had reported anything. The page was then built from the platform's generic layout instead of the type's own: none of the type's views, and — for a type that had genuinely failed to build — no error panel either. The page was not blank and nothing timed out; data flowed and the page rendered. It simply never showed what it was supposed to show, and because the decision is only made once, it stayed that way.

The cause was that the wait and the code acting on its result read the same record two different ways. A record that has just been created, or that has just arrived from another part of the mesh, is carried in a raw form until it is unpacked. The code that acts on the result unpacks it; the wait did not, so to the wait every such record looked like "not a type at all — nothing to wait for", and it finished on the spot. Whichever form the record happened to be in at that instant decided whether your page came out right, which is why it came and went.

Both now read the record the same way. The wait ends when the build has actually reported, in whichever form the record arrives.