Steps to reproduce the issue:
1. Download and open attached project.
2. Notice that after a few seconds Unity Editor crashes on:

#0 0x00000100dbfe50 in ProceduralMaterialData::GetTextureRawData(unsigned int) const
#1 0x0000010167cf4b in SubstanceImporter::OnTexturesModified(ProceduralMaterial*, std::map<ProceduralTexture*, SubstanceTexture_, std::less<ProceduralTexture*>, stl_allocator<std::pair<ProceduralTexture* const, SubstanceTexture_>, (MemLabelIdentifier)77, 16> >&)
#2 0x00000100dee973 in SubstanceSystem::Update(bool)
#3 0x00000101a73917 in Application::TickTimer()
#4 0x007fff8ca51350 in __NSFireTimer
#5 0x007fff98b849f4 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
#6 0x007fff98b84683 in __CFRunLoopDoTimer
#7 0x007fff98b841da in __CFRunLoopDoTimers
#8 0x007fff98b7b6d1 in __CFRunLoopRun
#9 0x007fff98b7ad38 in CFRunLoopRunSpecific
#10 0x007fff9b4b2d55 in RunCurrentEventLoopInMode
#11 0x007fff9b4b2b8f in ReceiveNextEventCommon
#12 0x007fff9b4b29cf in _BlockUntilNextEventMatchingListInModeWithFilter
#13 0x007fff8bd53f3a in _DPSNextEvent
#14 0x007fff8bd53369 in -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:]
#15 0x007fff8bd47ecc in -[NSApplication run]
#16 0x007fff8bd11162 in NSApplicationMain
#17 0x00000101d6b019 in EditorMain(int, char const**)
#18 0x00000101d6b6d9 in main
#19 0x000001000026d4 in start

Reproduced with:
5.4.0f2, 5.4.0f3, 5.5.0a4, 5.5.0a6.

Cannot reproduce with:
5.1.5f1, 5.2.5f1, 5.3.5f1, 5.3.6p3, 5.4.0p2, 5.5.0a3.

3. Navigate to the “vfx_PlasmaExplosion” asset in the "Project" window (“Assets->Prefabs->General VFX”) and select it.
4. In the “Inspector” window change “Prticles/Alpha Blended Premultiply” shader to “Standard”.
5. Notice that Unity Editor crashes on:

#0 0x00000100dbe17c in ProceduralMaterialData::GetSubstancePackageName()
#1 0x00000101676145 in SubstanceImporter::BindTexturesToShader(ProceduralMaterial&)
#2 0x00000101673f73 in SubstanceImporter::GenerateSubstanceMaterial(TiXmlDocument&, SubstanceArchive&, SubstanceHandle_*, std::string const&, std::string const&, MaterialInstanceSettings*, MaterialImportOutput*, BuildTargetPlatform, bool)
#3 0x00000101678242 in SubstanceImporter::GenerateAssetData()
#4 0x0000010146972f in AssetDatabase::ImportAsset(UnityGUID, Asset&, std::string const&, std::string const&, int, UpdateAssetOptions, std::basic_string<char, std::char_traits<char>, stl_allocator<char, (MemLabelIdentifier)1, 16> > const&, bool, InstanceIDLocalIdentifierLookup&, dynamic_array<Object*, 8ul>&)
#5 0x0000010146e044 in AssetDatabase::UpdateAsset(UnityGUID const&, UnityGUID const&, UpdateAssetOptions, Hash128, AssetImportingTimerStats*)
#6 0x000001014b991a in AssetInterface::ProcessAssetsImplementation(double&, AssetInterface::CancelBehaviour, UpdateAssetOptions)
#7 0x000001014b8c4f in AssetInterface::StopAssetEditing(AssetInterface::CancelBehaviour, UpdateAssetOptions)
#8 0x000001014c1168 in AssetInterface::ImportAssets(std::set<UnityGUID, std::less<UnityGUID>, std::allocator<UnityGUID> > const&, UpdateAssetOptions)
#9 0x0000010167b180 in SubstanceImporter::OnShaderModified(ProceduralMaterial&)
#10 0x0000011b36f0aa in (wrapper managed-to-native) UnityEditor.SubstanceImporter:OnShaderModified (UnityEngine.ProceduralMaterial) + 0xfa (0x11b36efb0 0x11b36f0d9) [0x116e40330 - Unity Child Domain]
#11 0x0000011ae73a68 in UnityEditor.ProceduralMaterialInspector:OnInspectorGUI () + 0x718 (0x11ae73350 0x11ae73ee4) [0x116e40330 - Unity Child Domain]
#12 0x0000011ad1c889 in UnityEditor.InspectorWindow:DrawEditor (UnityEditor.Editor,int,bool,bool&,UnityEngine.Rect&) + 0x1909 (0x11ad1af80 0x11ad1cd44) [0x116e40330 - Unity Child Domain]
#13 0x0000012fc71c29 in UnityEditor.InspectorWindow:DrawEditors (UnityEditor.Editor[]) + 0x919 (0x12fc71310 0x12fc71f98) [0x116e40330 - Unity Child Domain]
#14 0x0000012fc6f872 in UnityEditor.InspectorWindow:OnGUI () + 0x302 (0x12fc6f570 0x12fc6fe04) [0x116e40330 - Unity Child Domain]
#15 0x000001230c9cda in (wrapper runtime-invoke) object:runtime_invoke_void__this__ (object,intptr,intptr,intptr) + 0xfa (0x1230c9be0 0x1230c9e0d) [0x116e40330 - Unity Child Domain]
#16 0x0000010a5a9e06 in mono_get_runtime_build_info
#17 0x0000010a6d4406 in mono_runtime_invoke
#18 0x0000010a6da144 in mono_runtime_invoke_array
#19 0x0000010a698acb in mono_register_jit_icall
#20 0x00000123c4fe53 in (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&) + 0x103 (0x123c4fd50 0x123c4fe82) [0x116e40330 - Unity Child Domain]
#21 0x00000123c4f8ac in System.Reflection.MonoMethod:Invoke (object,System.Reflection.BindingFlags,System.Reflection.Binder,object[],System.Globalization.CultureInfo) + 0x52c (0x123c4f380 0x123c4fa1f) [0x116e40330 - Unity Child Domain]
#22 0x00000123ccf306 in System.Reflection.MethodBase:Invoke (object,object[]) + 0x66 (0x123ccf2a0 0x123ccf315) [0x116e40330 - Unity Child Domain]
#23 0x00000125455b9d in UnityEditor.HostView:Invoke (string,object) + 0xbd (0x125455ae0 0x125455bc1) [0x116e40330 - Unity Child Domain]
#24 0x00000125455aa0 in UnityEditor.HostView:Invoke (string) + 0x60 (0x125455a40 0x125455ac4) [0x116e40330 - Unity Child Domain]
#25 0x0000012eb326f5 in UnityEditor.DockArea:OnGUI () + 0x26f5 (0x12eb30000 0x12eb32b74) [0x116e40330 - Unity Child Domain]
#26 0x000001230c9cda in (wrapper runtime-invoke) object:runtime_invoke_void__this__ (object,intptr,intptr,intptr) + 0xfa (0x1230c9be0 0x1230c9e0d) [0x116e40330 - Unity Child Domain]
#27 0x0000010a5a9e06 in mono_get_runtime_build_info
#28 0x0000010a6d4406 in mono_runtime_invoke
#29 0x000001011d6b1b in ScriptingInvocationNoArgs::Invoke(MonoException**)
#30 0x000001023aa89b in MonoBehaviourDoGUI(int, ObjectGUIState&, MonoBehaviour::GUILayoutType, int, ScriptingMethodMono, PPtr<MonoBehaviour>)
#31 0x0000010239a1e9 in IMGUIModule::MonoBehaviourDoGUI(int, ObjectGUIState&, MonoBehaviour::GUILayoutType, int, ScriptingMethodMono, PPtr<MonoBehaviour>)
#32 0x000001011add51 in MonoBehaviour::DoGUI(MonoBehaviour::GUILayoutType, int, int)
#33 0x00000101d63303 in GUIView::SendLayoutEvent(GUIState&)
#34 0x00000101d5e8eb in GUIView::OnInputEvent(InputEvent&)
#35 0x00000101d5fd79 in -[GUIOpenGLView renderRect:]
#36 0x00000101d79611 in -[OpenGLView drawRect:]
#37 0x00000101d63e18 in GUIView::RepaintAll(bool)
#38 0x00000101a76971 in Application::UpdateScene(bool)
#39 0x00000101a73839 in Application::UpdateSceneIfNeeded()
#40 0x00000101a72e93 in Application::TickTimer()
#41 0x007fff8ca51350 in __NSFireTimer
#42 0x007fff98b849f4 in __CFRUNLOOP_IS_CALLING_OUT_TO_A_TIMER_CALLBACK_FUNCTION__
#43 0x007fff98b84683 in __CFRunLoopDoTimer
#44 0x007fff98b841da in __CFRunLoopDoTimers
#45 0x007fff98b7b6d1 in __CFRunLoopRun
#46 0x007fff98b7ad38 in CFRunLoopRunSpecific
#47 0x007fff9b4b2d55 in RunCurrentEventLoopInMode
#48 0x007fff9b4b2a97 in ReceiveNextEventCommon
#49 0x007fff9b4b29cf in _BlockUntilNextEventMatchingListInModeWithFilter
#50 0x007fff8bd53f3a in _DPSNextEvent
#51 0x007fff8bd53369 in -[NSApplication _nextEventMatchingEventMask:untilDate:inMode:dequeue:]
#52 0x007fff8bd47ecc in -[NSApplication run]
#53 0x007fff8bd11162 in NSApplicationMain
#54 0x00000101d6a039 in EditorMain(int, char const**)
#55 0x00000101d6a6f9 in main
#56 0x00000100002764 in start

This crash occurred only with Unity 5.4.0f1.