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:
- Known issues with DisplayLink on macOS 10.12 (Sierra)
- Known issues with DisplayLink on OS X 10.9, 10.10 and 10.11 (Mavericks, Yosemite and El Capitan)
- More Information about DisplayLink issues on macOS
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 "Metal" or if that doesn't work either to "OpenGL" or "Core Graphics (Quartz)"
We've contacted DisplayLink about the issue and are currently waiting for their answer.