BuildFrame returned false (skip frame) when the game view had no
primary camera, skipping the WaitFence/ResetFence/submit chain - the
frame-slot fence never got signaled, so the next WaitFence on that
slot blocked forever. Reproduced instantly by playing an empty scene
with embedded PIE; latent in manual fullscreen preview too.
Game view now falls back to the editor camera instead of skipping the
frame, keeping the per-slot fence cadence intact. Viewport warning
text updated to mention the editor-view fallback.
atdunbg
c083ee5cb7