A craft with no engine had nothing to stage, so the staging panel's conversion re-ran every frame and cleared the selection — the Configuration panel ignored every click.
Six of the eight flight-view panel toggles (and the pause/warp controls) were being laid out on a second row of a 34px bar, which meant they were drawn off it.
The Objectives panel opened inside the Guidance panel, which occupies the same column.
The Controls panel grew sideways over the navball.
Rendezvous had a toggle button that opened nothing. It now opens either way, and says what it is waiting for.
The Load Path panel re-imposed its own height every frame, so it could not be resized.
A vehicle with a thrust-to-weight under 1 fell through the ground on launch. The flight's only surface was the planet's datum, and the launch complex sits 70.9m above it — it now settles onto the pad, and is destroyed if it arrives hard.
Career integrity
Engine thrust and specific impulse are fixed to the part in career mode, and enforced when a craft is loaded. One shipped craft was flying an engine at 1,800,000N and 361s against a part that is 900,000N and 315s.
Booster and tank diameter are fixed the same way — a solid motor's thrust is derived from its geometry, so a wider one is a bigger one.
Craft files whose parts name no catalogue part are loadable in sandbox only. Nothing about such a part can be checked.
The authored data (parts, tech tree, contracts, science) is compiled into the executable rather than read from a folder beside it. Mods are still loaded from disk.
Removed the Reload content button from the VAB.
Interface
The parts palette has a tab per category, wrapped across rows so every category is visible, and hides categories with nothing unlocked in them yet.
Craft File, Configuration and Crew are now one panel with tabs; Engineering, Staging and Load Path are another. Both can be moved and resized.
A flight now opens with Telemetry, Guidance, Objectives, Stage Info and Controls. Everything else has a button on the top bar.
Deploy Parachutes now reads Arm Parachutes, which is what the button does.
Removed the redundant Research section from the Program screen — the tech tree has its own view.