Comment 8 for bug 2020782

Reproducer:

-- Grab a fresh Ubuntu 22.04 VM, then install NICE DCV Server & NICE Xdcv --

# Exit graphical mode
sudo systemctl isolate multi-user.target
# Install `ssh` & import id (optional)
sudo apt -y install openssh-server
ssh-import-id <your-lp-id>
# Disable wayland
sudo sed -i "s/WaylandEnable=True/WaylandEnable=false/" /etc/gdm3/custom.conf
# Install NICE DCV Server & Nice XDCV
cd /tmp
wget https://d1uj6qtbmh3dt5.cloudfront.net/NICE-GPG-KEY
gpg --import NICE-GPG-KEY
wget https://d1uj6qtbmh3dt5.cloudfront.net/2023.0/Servers/nice-dcv-2023.0-15065-ubuntu2204-x86_64.tgz
tar -xvzf nice-dcv-2023.0-15065-ubuntu2204-x86_64.tgz
cd nice-dcv-2023.0-15065-ubuntu2204-x86_64
sudo apt -y install ./nice-dcv-server_2023.0.15065-1_amd64.ubuntu2204.deb
sudo apt -y install ./nice-xdcv_2023.0.547-1_amd64.ubuntu2204.deb
# Add "dcv" user to "video" group:
sudo usermod -aG video dcv
# Start dcv server:
sudo systemctl start dcvserver
# Create a session:
sudo dcv create-session my-test-session --owner=test

-- client --
# Install NICE DCV client and connect to the dcv host
wget https://d1uj6qtbmh3dt5.cloudfront.net/2023.0/Clients/nice-dcv-viewer_2023.0.5483-1_amd64.ubuntu2204.deb
dpkg -i nice-dcv-viewer_2023.0.5483-1_amd64.ubuntu2204.deb
dcvviewer https://<vm-ip>:8443#my-test-session

# Then, try to change the display scale, and click "revert settings", the session should freeze
# gnome-shell log should contain similar log messages to the following:
May 30 15:59:03 test-2 gnome-shell[4906]: Failed to restore previous configuration: Invalid mode 3840x1352 (59,963089) for monitor 'unknown unknown'
May 30 15:59:03 test-2 gnome-shell[4906]: Failed to use linear monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown'
May 30 15:59:03 test-2 gnome-shell[4906]: Failed to use fallback monitor configuration: Invalid mode 800x600 (-nan) for monitor 'unknown unknown'
May 30 15:59:03 test-2 gnome-shell[4906]: Impossible to set scaling on crtc 59 to 1,000000, error id 2