Troubleshooting Virtual Displays

This page covers common issues with virtual displays. If you encounter a problem not listed here, please check the general troubleshooting section or contact support.

Extended Windows Not Appearing in Chrome (macOS)

Symptom:

When using virtual displays on macOS with Chrome, extended windows or additional monitors don’t appear, or they open and immediately close.

Root Cause:

Chrome’s pop-up blocking feature may be preventing extended windows from opening.

Solution:

  1. Disable pop-up blocking in Chrome:

    • Open Chrome and click the Menu (three dots) in the top-right corner

    • Select Settings > Privacy and security > Site settings

    • Scroll down and click Pop-ups and redirects

    • Find your Reemo portal URL and set it to Allow

  2. Alternatively, use a different browser:

    • Try using Safari, Firefox, or another browser where you don’t encounter this issue

Once you’ve made these changes, restart your Reemo session and try opening extended displays again.

No Virtual Display Available (Linux)

Symptom:

On a Linux remote computer, the Add button of the virtual monitors setting produces nothing, or no virtual display ever appears in the session.

Root Cause:

On Linux, Reemo creates a virtual display by activating a video output that no physical monitor occupies. The following situations leave it with no output to activate:

  • The remote computer uses NVIDIA graphics with the proprietary driver, EVDI is not installed, and Reemo could not declare the ports of the card:

    • The machine has not been restarted since the agent was installed.

    • A monitor is plugged into another graphics card.

    • No DisplayPort port is free after the physical monitors.

    • The declaration was withdrawn because the X server did not show the ports at boot.

  • Every output of the graphics card already drives a physical monitor.

  • The remote session runs on Wayland. Linux capture and virtual displays both require X.Org.

  • Virtual displays are turned off in the agent configuration.

Solution:

  1. Check the graphics card of the remote computer:

    • On NVIDIA graphics with the proprietary driver, restart the machine after installing the agent, and plug the physical monitors into the first ports of the card. See Virtual displays on Linux.

    • If the /opt/reemo/nvidia-ports.failed file exists, Reemo withdrew the declaration of the ports: delete this file, then restart the machine. After a graphics card change, also delete the /opt/reemo/nvidia-ports file.

    • If these conditions cannot be met, install the EVDI kernel module, then reboot the machine.

    • On Intel or AMD graphics, free an output by disconnecting a physical monitor, or install EVDI to obtain 5 virtual displays whatever the physical outputs.

  2. Check the session type:

    • Open an X.Org session on the remote computer. Virtual displays are not available under Wayland.

  3. Check the agent configuration:

    • Verify that virtual_monitors is not set to false in the [linux] section of reemo.ini.

After installing EVDI, restart the remote computer and reconnect to the session: the Add button provisions virtual displays from that point on.