Xcelium 26.03 menus and toolbars rendered incorrectly when accessed through VNC on Rocky Linux 8.10. Resizing or maximizing a window could leave parts of the old image behind. Switching the remote desktop session from GNOME to Xfce4 stopped the corruption in this setup.
GNOME worked when used directly on the host. Changing the VNC server did not help. The useful change was the desktop running inside the VNC session, not a reinstall of Xcelium.
Where the display broke
The host ran Rocky Linux 8.10 and Cadence Xcelium 26.03. The reported VNC setup used TigerVNC on the host and UltraVNC Viewer on Windows 11.
| Connection and desktop | Observed result |
|---|---|
| GNOME-based desktop through VNC | Menus, toolbars and resized windows rendered incorrectly |
| GNOME used directly on the host | The corruption did not reproduce |
| A different VNC server | No improvement |
| Xfce4 through VNC | The same GUI operations rendered normally |
This narrowed the problem to the remote-desktop combination, but did not identify a faulty component. The tests did not isolate GNOME Shell, the window manager, the compositor or X11. Xfce4 is a working alternative for this case, not proof that every Xcelium display problem has the same cause.
Install Xfce without replacing the host’s desktop
The commands below are for Rocky Linux 8. They require administrator access to install packages; editing your own VNC startup file does not. Keep an SSH connection or another way to reach the host before restarting the graphical session, and save work inside VNC first.
Enable the repositories used to obtain Xfce and its dependencies:
sudo dnf config-manager --set-enabled powertools
sudo dnf install -y epel-release
powertools is the Rocky Linux 8 repository name. Do not replace it with crb just because a Rocky Linux 9 guide uses that name.
List the available groups before installing:
sudo dnf grouplist
sudo dnf groupinstall -y "Xfce"
Run the second command only after Xfce appears in the list. If it is missing, check the enabled repositories and package metadata first. The Rocky Linux Xfce guide has a separate Rocky Linux 8 section. It also discusses a local login manager; changing the physical host’s login manager is not the change described here.
Select Xfce in the VNC session
The original setup used ~/.vnc/xstartup to launch the desktop. These instructions apply only if your VNC installation actually reads that script. TigerVNC packages can instead select a desktop through a session setting; see the RHEL VNC configuration documentation. Creating an unused xstartup file will not change such a session.
For the script-based setup, back up the existing file and edit it as the VNC user:
cp -a ~/.vnc/xstartup ~/.vnc/xstartup.bak
vi ~/.vnc/xstartup
Use a different backup name if .bak already contains a copy you need to keep. If the source file does not exist, stop and identify how your session starts rather than assuming this path applies.
The startup script used for Xfce4 is:
#!/bin/sh
unset SESSION_MANAGER
unset DBUS_SESSION_BUS_ADDRESS
exec startxfce4
The two unset lines remove inherited session settings before launching the new desktop. Make the script executable:
chmod +x ~/.vnc/xstartup
Stop and restart only the VNC session you are changing, then reconnect from the viewer. Closing the viewer alone may leave the old desktop running. The service name and restart command depend on the installed TigerVNC package and display number, so use the configuration already assigned to that user rather than stopping every VNC session on a shared machine.
Repeat the operations that used to fail
After reconnecting, check that the desktop is Xfce rather than the previous GNOME session. Open Xcelium, open the affected menus and toolbars, and repeat the resize, maximize and full-screen operations.
Those operations no longer produced the corruption in the reported setup. If the old desktop still appears, check which startup configuration the VNC service reads. If the session fails to start at all, restore the saved startup file through SSH and restart that session. Neither case calls for changing the Xcelium installation first.
