Hello colin_liew85

is it another OS on the systems?

I heard that on win11 systems often these kind of errors occur with SmartClient.

you can also try (if you are not able to update OS on the HMI to latest Version) other VNC Clients work without the error like TightVNC or UltraVNC

Bye Murof

Hello

which TIA Portal Version do you use?

You can update the you Panel (TP900 Comfort) to the newest OS Version V17.0.0.8

you can use the PIU Updater for installing the image version in your TIA portal. Then do a OS Update and transfer for the Project again:

https://support.industry.siemens.com/cs/de/en/view/109825750

Bye Murof