AI Pathfinding Lag
TPS drops because mobs are spending excessive time on pathfinding. Large numbers of mobs, or mobs trying to reach unreachable targets, make the AI recalculate paths constantly.
What does this error mean?
Mobs use pathfinding to navigate, an expensive calculation. 'Excessive pathfinding' means too many path computations per tick, usually from crowded mobs or mobs endlessly retrying an impossible route, which eats the tick budget.
Excessive pathfinding
Most Common Causes
- Too many mobs concentrated in one area (farms).
- Mobs pathing toward unreachable targets repeatedly.
- Villagers trying to reach blocked workstations/beds.
- Complex terrain forcing heavy path searches.
- A mod adding pathing-heavy AI.
How To Diagnose
- Use spark to attribute tick time to pathfinding/AI.
- Locate dense mob clusters.
- Look for mobs/villagers stuck against obstacles.
- Note any AI-heavy mod in the profile.
Recommended Fixes
- Reduce mob density
Cap farms and lower mob counts so fewer entities path at once. - Remove impossible targets
Fix layouts so mobs/villagers are not endlessly pathing to blocked spots. - Tune AI on Paper
Use Paper's mob AI/activation-range settings to cut needless pathing. - Simplify problem areas
Smooth terrain or reposition workstations to ease pathfinding.
Frequently Asked Questions
It searches many possible routes each time, multiplied across many mobs, it adds up fast.
Yes, villagers repeatedly pathing to unreachable beds/jobs are a common cause.
Yes, activation ranges and AI tuning reduce how often distant mobs run pathfinding.