I can't reproduce this at will, but I have had MC crash twice recently when launching the UI while a recording was happening. If you want to look at the log and crash dump let me know who to send it to.
This is the output where it crashes:
2976827: 3196: General: CMainUIWnd::Resize: Finish (187 ms)
2976827: 3196: General: CMCUICore::SetMode: Finish (577 ms)
2976827: 3196: General: CWebViewWebWnd::OnTitleChange: Start
2976827: 3196: General: CWebViewWebWnd::OnTitleChange: Title: Start
2976843: 3196: General: CWebViewWebWnd::OnTitleChange: Finish (16 ms)
2976843: 3196: General: CWebViewWebWnd::OnTitleChange: Start
2976843: 3196: General: CWebViewWebWnd::OnTitleChange: Title: Start
2976843: 3196: General: CWebViewWebWnd::OnTitleChange: Finish (0 ms)
2976843: 3196: General: COGLCore::Initialize: Start
2976843: 3196: General: COGLCore::Initialize: Stopping previous instances
2976843: 3196: General: COGLCore::InitializeContext: Start
2976843: 3196: General: COGLCore::InitializeContextWindows: Start
2976843: 3196: General: TopLevelExceptionFilter: Unhandled exception -- program crashing
2976843: 3196: General: TopLevelExceptionFilter: Message: 15, wParam: 0, lParam: 0
2976843: 3196: General: RunProgram: Start
2976843: 3196: General: RunProgram: Filename: C:\Program Files (x86)\J River\Media Center 22\JRCrashHandler.exe / Parameters: JRCrashInfo3192
2976843: 3196: General: RunProgram: Performing ShellExecute...