4.9 code breaks, will not compile

Hi, I am trying to move a code project from 4.7 to 4.9, and am getting breaks on compile.

Firstly, in commands.h, at the line

/** Get the singleton instance of this set of commands. */
static const CommandContextType& Get()
{
	return *(Instance.Pin());  //breaks here
}

If i continue, it hits WindowsPlatformOutputDevices.cpp, at the line:

void FOutputDeviceWindowsError::Serialize( const TCHAR* Msg, ELogVerbosity::Type Verbosity, const class FName& Category )
    {
    	FPlatformMisc::DebugBreak();  //Breaks here

If i continue that, it crashes the process and will not build.

Please help!

Ah, I was missing a few lines in a UI button generation:

PRAGMA_DISABLE_OPTIMIZATION
#define LOCTEXT_NAMESPACE  

void FVP_EditorPluginCommands::RegisterCommands()
{
	//create button etc
}
PRAGMA_ENABLE_OPTIMIZATION
#undef LOCTEXT_NAMESPACE

fixed it.