Selecting NGUI input field, getting Access violation error.

Getting the error only when deploying on PC.

Exception doesn't occur when deploying on touchscreen tablet, except the fact that's impossible to open touch screen keyboard by selecting an input field.

Reproducible on 5.3.0f4, 5.3.1f1, 5.3.1p3;

Repro steps:
1. open project "unity_ms_BUG_UIInput.zip";
2. build to UWP xaml platform.
3. build and run generated project on x64 solution platform.
4. when application starts, try to select any input field. Access violation error appears in the screen.

Call stack output:
ntdll.dll!00007fff8bc3e609()Unknown
UnityPlayer.dll!PlatformMutex::Lock() Line 42C++
UnityPlayer.dll!Mutex::Lock() Line 62C++
UnityPlayer.dll!Mutex::AutoLock::AutoLock(Mutex & mutex) Line 29C++
UnityPlayer.dll!WinRTKeyboard::Show(const std::basic_string<char,std::char_traits<char>,stl_allocator<char,65,16> > & text, KeyboardOnScreen::KeyboardTypes type, bool autocorrection, bool multiline) Line 245C++
UnityPlayer.dll!KeyboardOnScreen::setActive(bool flag) Line 173C++
UnityPlayer.dll!TouchScreenKeyboard_Set_Custom_PropActive(__int64 self_, int value) Line 274C++
UnityEngineDelegates.dll!00007fff516a5e35()Unknown
[External Code]
coreclr.dll!00007fff57016420()Unknown
[External Code]