Issue
In some office environments, strict firewall or VPN settings can block the communication required for license activation, even when the system is connected to the internet. This may prevent successful activation of Sentinel LDK licenses.


Cause
Windows Firewall may be blocking port 1947, which is used by Sentinel LDK for license authorization and activation.


Solution (Windows Firewall)
You can allow this communication by opening port 1947 using PowerShell.


Steps:

  1. Open PowerShell as Administrator
  2. Run the following commands:
netsh advfirewall firewall add rule name="Sentinel LDK TCP 1947" dir=in action=allow protocol=TCP localport=1947

netsh advfirewall firewall add rule name="Sentinel LDK UDP 1947" dir=in action=allow protocol=UDP localport=1947

Notes:

  • These commands create inbound rules to allow both TCP and UDP traffic on port 1947.
  • This solution applies to Windows Firewall only.
  • If your system uses third-party firewall or security software, additional configuration may be required.


Result
After applying these changes, retry the license activation process. Communication with the Sentinel LDK service should now be allowed.