[EMFX][ATOM] crash during mesh reload (#1301)

* Fixed a crash when entering game mode, removing a mesh and re-adding mesh.

Gems/Atom/Feature/Common/Code/Source/SkinnedMesh/SkinnedMeshInputBuffers.cpp

@@ -629,6 +629,11 @@ namespace AZ
 
                 Data::Asset<RPI::ModelLodAsset> lodAsset;
                 modelLodCreator.End(lodAsset);
+                if (!lodAsset.IsReady())
+                {
+                    // [GFX TODO] During mesh reload the modelLodCreator could report errors and result in the lodAsset not ready.
+                    return nullptr;
+                }
                 modelCreator.AddLodAsset(AZStd::move(lodAsset));
 
                 lodIndex++;

Gems/AtomLyIntegration/EMotionFXAtom/Code/Source/ActorAsset.cpp

@@ -311,7 +311,8 @@ namespace AZ
             Data::Asset<RPI::ModelAsset> modelAsset = actor->GetMeshAsset();
             if (!modelAsset.IsReady())
             {
-                AZ_Error("CreateSkinnedMeshInputFromActor", false, "Attempting to create skinned mesh input buffers for an actor that doesn't have a loaded model.");
+                AZ_Warning("CreateSkinnedMeshInputFromActor", false, "Check if the actor has a mesh added. Right click the source file in the asset browser, click edit settings, "
+                    "and navigate to the Meshes tab. Add a mesh if it's missing.");
                 return nullptr;
             }
 

Gems/AtomLyIntegration/EMotionFXAtom/Code/Source/AtomActorInstance.cpp

@@ -456,9 +456,8 @@ namespace AZ
         void AtomActorInstance::Create()
         {
             Destroy();
-
             m_skinnedMeshInputBuffers = GetRenderActor()->FindOrCreateSkinnedMeshInputBuffers();
-            AZ_Error("AtomActorInstance", m_skinnedMeshInputBuffers, "Failed to get SkinnedMeshInputBuffers from Actor.");
+            AZ_Warning("AtomActorInstance", m_skinnedMeshInputBuffers, "Failed to create SkinnedMeshInputBuffers from Actor. It is likely that this actor doesn't have any meshes");
             if (m_skinnedMeshInputBuffers)
             {
                 m_boneTransforms = CreateBoneTransformBufferFromActorInstance(m_actorInstance, GetSkinningMethod());