TL;DR: To revive a dead community, diagnose the cause with member interviews (not guesses), prune ruthlessly, personally re-activate your 20 most valuable ex-contributors, relaunch with a 14-day event sprint, and install a weekly rhythm so it never dies again. Most dead groups are not dead — they are dormant, and dormancy is reversible in 30 to 60 days. A silent group feels like failure, but...