Steps to reproduce:
1. Create a new Unity project
2. Build for WSA Windows 8.1 SDK
3. Open VS solution
4. Deploy on device with touch input (Microsoft Surface) using Debug/x86 configuration

Result: Exception is thrown: Run-Time Check Failure #2 - Stack around the variable '_Cat' was corrupted.

Reproducible with: 5.6.0a1

Not reproducible with: 5.4.2p1

Call Stack:
UnityPlayer.dll!std::copy<ColorRGBA32 const *,StrideIterator<ColorRGBA32> >(const ColorRGBA32 * _First, const ColorRGBA32 * _Last, StrideIterator<ColorRGBA32> _Dest) Line 2134 C++
UnityPlayer.dll!Mesh::SetColors(const ColorRGBA32 * data, unsigned int count) Line 952 C++
UnityPlayer.dll!SetMeshComponentFromArrayFromScript(Mesh & mesh, InternalScriptingShaderChannel channel_, InternalScriptingVertexChannelType format_, int dim, WinRTScriptingObjectWrapper array, int arraySize) Line 301 C++
UnityPlayer.dll!Mesh_CUSTOM_SetArrayForChannelImpl(void * self_, InternalScriptingShaderChannel channel, InternalScriptingVertexChannelType format, int dim, __int64 values_, int arraySize) Line 177 C++
UnityEngineDelegates.dll!60dee17a() Unknown
[Frames below may be incorrect and/or missing, no symbols loaded for UnityEngineDelegates.dll]
[External Code]
UnityPlayer.dll!metro_invoke_method(ScriptingMethodPtr method, WinRTScriptingObjectWrapper object, ScriptingArguments * arguments, WinRTScriptingObjectWrapper * exception, bool convertArgs) Line 66 C++
UnityPlayer.dll!scripting_method_invoke(ScriptingMethodPtr method, WinRTScriptingObjectWrapper object, ScriptingArguments & arguments, WinRTScriptingObjectWrapper * exception, bool convertArgs) Line 789 C++
UnityPlayer.dll!ScriptingInvocation::Invoke(WinRTScriptingObjectWrapper * exception, bool convertArguments) Line 290 C++
UnityPlayer.dll!ScriptingInvocation::Invoke() Line 80 C++
UnityPlayer.dll!UI::CanvasManager::WillRenderCanvases() Line 409 C++
UnityPlayer.dll!`UI::InitializeCanvasManager'::`23'::UIEventsWillRenderCanvasesstruct::Forward() Line 434 C++
UnityPlayer.dll!PlayerUpdateCanvases() Line 874 C++
UnityPlayer.dll!`InitPlayerLoopCallbacks'::`23'::PostLateUpdatePlayerUpdateCanvasesstruct::Forward() Line 1248 C++
UnityPlayer.dll!PlayerLoop() Line 196 C++
UnityPlayer.dll!metro::MainLoop(bool performRendering) Line 202 C++
UnityPlayer.dll!UnityPlayer::AppCallbacks::DoPerformUpdateAndRender() Line 1306 C++
UnityPlayer.dll!UnityPlayer::AppCallbacks::PerformUpdateAndRender() Line 1262 C++
UnityPlayer.dll!UnityPlayer::AppCallbacks::_AppThreadImplementation(void * param) Line 180 C++
UnityPlayer.dll!UnityPlayer::AppCallbacks::_AppThread(void * param) Line 212 C++
UnityPlayer.dll!win32::CreateThread::__l29::<lambda>(Windows::Foundation::IAsyncAction ^ __formal) Line 276 C++
[External Code]