The Systems Management agent uses Ultra VNC which runs on TCP port 5900. When issues occur, it is mainly because of basic connection issues normally due to firewall/proxy misconfiguration.
Additionally, Ultra VNC is installed as part of the PCSM agent installation process and runs as a Windows service called uvnc_service. Thus, sometimes, the following issues associated with uVNC can occur:
Error message when trying to initiate a screen share session from PCSM agent browser:
Could not connect to the remote device. Please ensure you are using the correct VNC password and that the VNC Service is started on the remote device
Check both the correct VNC password and that the VNC service (uvnc_service) is started.
Additional VNC services running on the remote device can cause VNC password conflicts.
It is not recommended to run additional VNC services alongside PCSM.
If there are no additional VNC installations on the target device, then ensure that the PCSM VNC service (uvnc_service) is running.