In Royal TSX 3.0 we added a new (layer-based) rendering engine to our RDP implementation. This new engine improves performance while reducing power consumption so it's a big improvement.

Unfortunately, this way of rendering the remote screen is problematic when using certain USB adapters to connect external monitors. Specifically, USB adapters/video controllers by DisplayLink have several known issues:

If you're not sure whether or not your Adapter/Docking Station/Converter is using a chip by DisplayLink, you can check in the "System Information.app" by going to "USB", finding your device and looking for "Manufacturer: DisplayLink" in the details pane.

Since this mode uses hardware/GPU acceleration to render the remote screen, it's also impossible to use this mode when macOS is run inside a virtual machine or under certain circumstances when connected to a real Mac remotely using Apple Remote Desktop/Screen Sharing.

Until either DisplayLink or Apple correct these issues, here's a workaround for getting RDP connections working properly when using DisplayLink hardware or in installations where no GPU acceleration is available:

  • Open the "Preferences"
  • Navigate to "Connection Types - Remote Desktop"
  • Switch the "Rendering Engine" to "OpenGL" or if that doesn't work either to "Core Graphics (Quartz)"

We've contacted DisplayLink about the issue and are currently waiting for their answer.