Crash on GetInputDevice when trying out Pixel Streaming

I have been trying to get Pixel Streaming to work in a C++ project converted from a 4.19 project, but both when running a packaged game and as a standalone game it seems to crash. When running a deployed game it crashes when pressing play in the html player UI.

When running as a standalone game it crashes on an assertion for FPixelStreamingPlugin::GetInputDevice().

I tried by also running a project created from the 2d scroller template and that seems to work fine, so I’m suspecting there’s something specific for this project rather than the whole pixel streaming pipeline.

Anybody seen something similar, or can shed some light on where to keep debugging?

UE4Editor_Core!FDebug::AssertFailed() [d:\build\++ue4\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:417]
UE4Editor_PixelStreaming!FPixelStreamingPlugin::GetInputDevice() [d:\build\++ue4\sync\engine\plugins\experimental\pixelstreaming\source\pixelstreaming\private\pixelstreamingplugin.cpp:123]
UE4Editor_PixelStreaming!FProxyConnection::FProxyConnection() [d:\build\++ue4\sync\engine\plugins\experimental\pixelstreaming\source\pixelstreaming\private\proxyconnection.cpp:18]
UE4Editor_PixelStreaming!FStreamer::FStreamer() [d:\build\++ue4\sync\engine\plugins\experimental\pixelstreaming\source\pixelstreaming\private\streamer.cpp:104]
UE4Editor_PixelStreaming!FPixelStreamingPlugin::OnBackBufferReady_RenderThread() [d:\build\++ue4\sync\engine\plugins\experimental\pixelstreaming\source\pixelstreaming\private\pixelstreamingplugin.cpp:88]
UE4Editor_SlateRHIRenderer!FSlateRHIRenderer::DrawWindow_RenderThread() [d:\build\++ue4\sync\engine\source\runtime\slaterhirenderer\private\slaterhirenderer.cpp:916]
UE4Editor_SlateRHIRenderer!TGraphTask<TEnqueueUniqueRenderCommandType<`FSlateRHIRenderer::DrawWindows_Private'::`29'::SlateDrawWindowsCommandName,<lambda_43e86ee7c51f39979e9a39d40b280024> > >::ExecuteTask() [d:\build\++ue4\sync\engine\source\runtime\core\public\async\taskgraphinterfaces.h:829]
UE4Editor_Core!FNamedTaskThread::ProcessTasksNamedThread() [d:\build\++ue4\sync\engine\source\runtime\core\private\async\taskgraph.cpp:679]
UE4Editor_Core!FNamedTaskThread::ProcessTasksUntilQuit() [d:\build\++ue4\sync\engine\source\runtime\core\private\async\taskgraph.cpp:575]
UE4Editor_RenderCore!RenderingThreadMain() [d:\build\++ue4\sync\engine\source\runtime\rendercore\private\renderingthread.cpp:333]
UE4Editor_RenderCore!FRenderingThread::Run() [d:\build\++ue4\sync\engine\source\runtime\rendercore\private\renderingthread.cpp:467]
UE4Editor_Core!FRunnableThreadWin::Run() [d:\build\++ue4\sync\engine\source\runtime\core\private\windows\windowsrunnablethread.cpp:76]

This seems to have been fixed in 4.21.1