That if more than 5 HTC Vive VR trackers are connected, UE4 crashes

I want to use a continuous Transform( Tick → Transform) value of 9 vive tracker.

but

If there are more than five trackers, the unreal engine will be shutdown

Turning on the steam compositor allows nine tracker connections but cannot be continuous Transform( Tick → Transform)

What should I do?

Thank you

6 Tracker error
ㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡ

Assertion failed: Key.IsValid() [File:D:\Build++UE4\Sync\Engine\Source\Runtime\Slate\Private\Framework\Application\SlateApplication.cpp] [Line: 6343]

UE4Editor_Core!FDebug::AssertFailed() [d:\build++ue4\sync\engine\source\runtime\core\private\misc\assertionmacros.cpp:425]
UE4Editor_Slate!FSlateApplication::OnControllerButtonReleased() [d:\build++ue4\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:6345]
UE4Editor_SteamVRController!FSteamVRController::SendControllerEvents() [d:\build++ue4\sync\engine\plugins\runtime\steam\steamvr\source\steamvrcontroller\private\steamvrcontroller.cpp:430]
UE4Editor_ApplicationCore!FWindowsApplication::PollGameDeviceState() [d:\build++ue4\sync\engine\source\runtime\applicationcore\private\windows\windowsapplication.cpp:2259]
UE4Editor_Slate!FSlateApplication::PollGameDeviceState() [d:\build++ue4\sync\engine\source\runtime\slate\private\framework\application\slateapplication.cpp:1594]
UE4Editor!FEngineLoop::Tick() [d:\build++ue4\sync\engine\source\runtime\launch\private\launchengineloop.cpp:3474]
UE4Editor!GuardedMain() [d:\build++ue4\sync\engine\source\runtime\launch\private\launch.cpp:166]
UE4Editor!GuardedMainWrapper() [d:\build++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:144]
UE4Editor!WinMain() [d:\build++ue4\sync\engine\source\runtime\launch\private\windows\launchwindows.cpp:223]
UE4Editor!__scrt_common_main_seh() [f:\dd\vctools\crt\vcstartup\src\startup\exe_common.inl:283]
kernel32
ntdll