The renderer keeps drawing after the wallpaper view is torn down, so it touches a freed Metal texture. It started with 1.6.0, when the preview screen began reusing renderers.

Try first: Stop the display link in the view's teardown before releasing the texture.

Gallery thumbnails time out on slow connections because every tile starts its own request at once. Users see empty tiles, not a crash.

Try first: Cap concurrent thumbnail requests at four and retry once with a longer timeout.

Mixing a palette with fewer than three colors reads past the end of the array. Only custom palettes made in 1.6.0 can hit it.

Try first: Guard the blend loop on the palette's real count and fall back to the default palette.