Most of the are feedback errors.
WaypointMovementGenerator::LoadPath: Creature (Entry: 645 Guid: 79344) doesn't have waypoint path 0 <-- self explanatory.
Also checked code for handling this error and it shouldn't have crashed the server.
Spell entry 29705, effect 0 has EffectImplicitTargetA/EffectImplicitTargetB = TARGET_SCRIPT, but creature are not defined in `spell_script_target` <-- needs fixing but we need to know the target entry for it. https://vanilla-twinhead.twinstar.cz/?spell=29715
Summoned pet (Entry: 4661) not have pet stats data in DB <-- May have occurred because your players where higher levels than 60 which should now not occur. Were you using very high level players above 60?
NULL target for ACTION_T_CAST Creature (Entry: 7115 Guid: 40628) casting spell id # <-- May be a race condition with projectiles, the target is available when casted but not on hit when the projectile lands.