While there is no single "Complete All Quests" button, you can still use specific console commands to force quest completion or bypass bugs in The Witcher 3
Since every quest has a unique internal ID, you need the exact "fact" name to mark it done. witcher 3 complete quest console command patched
Quest Stage Locking: Post-4.0, many main quests and critical side quests now have internal "integrity checks." If you force-complete a quest, the game scans for prerequisite facts (e.g., q001_met_emhyr, q002_talked_vesemir). If those facts don’t exist naturally, the command fails silently or hard-crashes the game. While there is no single "Complete All Quests"
Then to clean orphaned quest flags (safe to run anytime): witcher 3 complete quest console command patched