To reproduce:
1. Open project
2. Open 'Scene'
3. Play scene

Expected: scene will be played and game object will be animated
Actual: editor crashes

Reproduced on: 5.6.0a1, f2, 2017.1.0a5
No repro on any 5.5 version

Note:
AvatarBuilder.BuildHumanAvatar method is used in 'VoxelSkinnedAnimationObjectCore' script
Also, if we will build scene, it will be built successfully and works properly, but after you close built scene it throws message, that app quit unexpectedly

========== OUTPUTING STACK TRACE ==================

0x00000001418974AA (Unity) mecanim::skeleton::SkeletonPoseComputeGlobalQ
0x00000001418974D7 (Unity) mecanim::skeleton::SkeletonPoseComputeGlobalQ
0x00000001412BF6FF (Unity) mecanim::human::HumanFixTwist
0x00000001412C4CB0 (Unity) mecanim::human::TwistSolve
0x000000014127A195 (Unity) mecanim::animation::EvaluateAvatarEnd
0x0000000140832E1B (Unity) Animator::Sample
0x0000000140836FBC (Unity) SampleAnimation
0x000000004E735C2B (Mono JIT Code) (wrapper managed-to-native) UnityEditor.AnimationMode:SampleAnimationClip (UnityEngine.GameObject,UnityEngine.AnimationClip,single)
0x000000004E7356CF (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\AnimationWindow\AnimationWindowControl.cs:287] UnityEditorInternal.AnimationWindowControl:ResampleAnimation ()
0x000000004E71DCDE (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\AnimationWindow\AnimationWindowControl.cs:207] UnityEditorInternal.AnimationWindowControl:PlaybackUpdate ()
0x000000004E71D75E (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\AnimationWindow\AnimEditor.cs:376] UnityEditor.AnimEditor:PlaybackUpdate ()
0x000000004E71D52B (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\AnimationWindow\AnimEditor.cs:287] UnityEditor.AnimEditor:Update ()
0x000000004E71D3F4 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\Animation\AnimationWindow\AnimationWindow.cs:76] UnityEditor.AnimationWindow:Update ()
0x0000000030076AC2 (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void__this__ (object,intptr,intptr,intptr)
0x000007FEDB405703 (mono) [c:\buildslave\mono\build\mono\mini\mini.c:4937] mono_jit_runtime_invoke
0x000007FEDB358425 (mono) [c:\buildslave\mono\build\mono\metadata\object.c:2623] mono_runtime_invoke
0x000007FEDB35E933 (mono) [c:\buildslave\mono\build\mono\metadata\object.c:3838] mono_runtime_invoke_array
0x000007FEDB31CE23 (mono) [c:\buildslave\mono\build\mono\metadata\icall.c:2750] ves_icall_InternalInvoke
0x0000000030040257 (Mono JIT Code) (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&)
0x000000003003E3B2 (Mono JIT Code) [/Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222] System.Reflection.MonoMethod:Invoke (object,System.Reflection.BindingFlags,System.Reflection.Binder,object[],System.Globalization.CultureInfo)
0x000000003011050F (Mono JIT Code) [/Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115] System.Reflection.MethodBase:Invoke (object,object[])
0x0000000036474945 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\HostView.cs:262] UnityEditor.HostView:Invoke (string,object)
0x00000000364747E7 (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\HostView.cs:255] UnityEditor.HostView:Invoke (string)
0x000000003B4B969C (Mono JIT Code) [C:\buildslave\unity\build\Editor\Mono\HostView.cs:330] UnityEditor.HostView:SendUpdate ()
0x000000003B4B9880 (Mono JIT Code) (wrapper delegate-invoke) UnityEditor.EditorApplication/CallbackFunction:invoke_void__this__ ()
0x000000003B4B95D9 (Mono JIT Code) [C:\buildslave\unity\build\artifacts\generated\common\editor\EditorApplicationBindings.gen.cs:249] UnityEditor.EditorApplication:Internal_CallUpdateFunctions ()
0x0000000030030A8E (Mono JIT Code) (wrapper runtime-invoke) object:runtime_invoke_void (object,intptr,intptr,intptr)
0x000007FEDB405703 (mono) [c:\buildslave\mono\build\mono\mini\mini.c:4937] mono_jit_runtime_invoke
0x000007FEDB358425 (mono) [c:\buildslave\mono\build\mono\metadata\object.c:2623] mono_runtime_invoke
0x00000001401A71B3 (Unity) mono_runtime_invoke_profiled
0x0000000141057B9B (Unity) CallStaticMonoMethod
0x0000000141059F17 (Unity) CallStaticMonoMethod
0x0000000141720046 (Unity) Application::TickTimer
0x00000001417EB40C (Unity) CrashCallback
0x00000001417ED054 (Unity) WinMain
0x0000000141ACFD9C (Unity) strnlen
0x0000000076EA59CD (kernel32) BaseThreadInitThunk
0x0000000076FDA561 (ntdll) RtlUserThreadStart

========== END OF STACKTRACE ===========