ImgMediaSource Problem in C++

I want to use png image sequence in my project. So, I create ImgMediaSource content to link png image sequence path. Then, I link in to c++ file following this code

static ConstructorHelpers::FObjectFinder<UMediaSource> source_readyObj(TEXT("/Game/Movies/source_ready"));
	m_readySource = source_readyObj.Object;

when I run in standalone mode (or reopen project) I found an error “Default Property warnings and errors: Error CDO Constructor (GSP_racing2Hud): Failed to find …”

240075-untitled.png

I tried in many ways such as create a new project or create a blueprint class and assign to it’s property, It still not work.

please help me, thankyou very much.

problem solved, Just change “UMediaSource” to “UImgMediaSource”. I wonder why its work on selected viewport.