Pure virtual not implemented (UAnimSequenceBase::GetAnimationPose() ) crash

I just finished upgrading from 4.7.6 to 4.9.2 and am now seeing a frequent crash when i play in the editor and move my character around the level.

I looked at the last error log from my game.

 [2015.10.15-02.49.37:043][642]LogWindows: === Critical error: ===
 LowLevelFatalError [File:d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\classes\animation\AnimSequenceBase.h] [Line: 137] 
  Pure virtual not implemented (UAnimSequenceBase::GetAnimationPose)

I do have a pretty good sized c++ project that I had to fix specific code changes to compile after the upgrade, but I do not reference anywhere the function GetAnimationPose(). I did have to redo a similar error in my own code to fix this when upgrading as a similar error was thrown. Not sure if related. It probably has something to do with my upgrade but I am not sure what the best way to debug this as the error thrown is referencing engine source code which I have not touched. I am new to the concept of the UE4 PURE_VIRTUAL macro as well so sorry for not understanding if this is obvious.

Any Help is greatly appreciated. Thanks!

UE4Editor_Core!FDebug::AssertFailed() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\core\private\misc\outputdevice.cpp:354]
UE4Editor_Engine!UAnimSequenceBase::GetAnimationPose() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\classes\animation\animsequencebase.h:137]
UE4Editor_Engine!FAnimNode_SequencePlayer::Evaluate() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\animation\animnode_sequenceplayer.cpp:63]
UE4Editor_Engine!FPoseLink::Evaluate() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\animation\animnodebase.cpp:127]
UE4Editor_Engine!FPoseLink::Evaluate() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\animation\animnodebase.cpp:127]
UE4Editor_Engine!FAnimNode_StateMachine::EvaluateState() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\animation\animnode_statemachine.cpp:890]
UE4Editor_Engine!FAnimNode_StateMachine::EvaluateTransitionStandardBlend() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\animation\animnode_statemachine.cpp:647]
UE4Editor_Engine!FAnimNode_StateMachine::Evaluate() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\animation\animnode_statemachine.cpp:594]
UE4Editor_Engine!FPoseLink::Evaluate() [d:\buildfarm\buildmachine_++depot+ue4-releases+4.9\engine\source\runtime\engine\private\animation\animnodebase.cpp:127]

So this seems pretty rare to my set up but was really hard to track down. I think I solved my issue as I was able to reproduce it consistently in my project after lots of crashing and testing different scenarios.

Long story short I have a c++ animinstance class that is responsible for setting up some variables for the Animation Blueprint to transition animations too and from based off of some triggers in my pawns. One of these is a generic override for a "GetReady animation that is toggled via c++ when the player character gets close to it. Otherwise the pawn just stays idle.

Basically the issue I was experiencing was; When I would run up to the enemy , the get ready animation toggled via c++ trigger, which in turn triggered a similar animation (both animation had anim notifys) to play via the animation blueprint state machine. Once transitioned to this state in the animation BP, I believe this is where it would crash the editor every time. Deleting the extra animation in my Anim Blueprint fixed the crashes. I am not sure honestly why I built it out the way i did to have this override of a “getReady” animation other than the fact of creating a more modular approach of my enemies animation states , so some just immediately start to attack, but for now this should be okay. I built that system a while ago :frowning: maybe back to the drawing board for that one … I am just happy I can now actually use 4.9.2 , what an improvement from 4.7.6.

Hope this rant helps someone else.

I just got this error and went on a wild goose chase and finally noticing it was because the override function return a null for the reload. And BOOM crash.

I just got this too each time I start the editor (so I’m locked out) after editing one animation blueprint. Incredible!

I got it by linking an AnimMontage to an AnimSequence player node in the anim blueprint.