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Posts tagged #browser-extension
of 10 - 10 Manifest V3 notes: service worker races, dropped registrations, and other quiet failures Six Manifest V3 behaviors that produce no error where anyone is looking: a startup reconcile racing itself into Duplicate script ID, content script registrations dropped on reload, an offscreen document that resolves before it can receive messages, an invalidated context, a test harness that loads nothing, and a runtime that blocks its host thread. Aug 19, 2026 · 4 min
Duplicate script ID - 09 Why captured subtitles don't line up: X-TIMESTAMP-MAP, stitched timelines, and four other causes Six reasons a correctly parsed subtitle track still lands in the wrong place in a browser video player, each with the symptom that identifies it: absolute MPEG-TS baselines, content versus presentation time, presentation time offsets, lazy fetching, per-URL clobbering, and arrival order. Aug 19, 2026 · 6 min
X-TIMESTAMP-MAP=LOCAL:00:00:00.000,MPEGTS:93900000