953-Error Communicating with Server

A 953 Error (often appearing as 953 - Error Communicating with Server) typically indicates a breakdown in communication between the GibbsCAM client and the NLO (Network Licensing Option) server. This usually occurs because the client cannot find the server on the network or the specific port is being blocked.

Below is a troubleshooting guide to resolve this, categorized by Server-side and Client-side checks.

Server-Side Verification

Before troubleshooting the user's computer, ensure the license server itself is healthy.

Check the License Service: Open GibbsRLMServer service (or the CimLmService for GC14 - GC 2023). 

Ensure the service is "Running." If it is stopped, click Start.

1. Verify the Ports:

GibbsCAM Reprise (RLM): Uses port 2764 for the Host line and port 2765 for the ISV line.

Ensure these ports are open in the Windows Firewall for both Inbound and Outbound rules.

On the client you can use Windows PowerShell (For Windows 8/10) to see if the client can communicate over the port that is being used.

• Open Windows PowerShell through the Start menu.
• Use the command "Test-NetConnection IPAddress -Port 2764" 
• Replace "IPAddress" with your server's IP Address
• Repeat the steps to test both ports.

This will test to see if the client computer has access to communicate over the port.  If it succeeds that means that the client is able to use that port.

Troubleshooting Failed Connections

If the connection test fails (TcpTestSucceeded : False), the network traffic is being interrupted before reaching the licensing service. Common causes include:

• Windows Firewall: Ensure inbound rules exist on the server to allow traffic through the specified port.
• Security Software: Antivirus or third-party endpoint security software may be blocking network calls.
• Network / Router Policies: Subnet routing, corporate hardware firewalls, or VPN policies may prevent access.

2. Communication failures can occur if the user's local roaming configuration file becomes corrupted. 

On the client delete the roaming XML from:

GC2025: C:\ProgramData\CAMBRIO\GibbsCAM\LicenseData\250.0

GC2026: C:\ProgramData\Gibbs\GibbsCAM\LicenseData\260.0

3. Resolving Server Name Resolution (DNS) Mismatches in the License File

If client workstations fail to locate or connect to the license server, the cause is often a DNS resolution mismatch—where the local network cannot correctly translate the server's hostname (e.g., SERVER01) into its active IP address.

Replacing the server hostname with its static IP address directly inside the client license file bypasses DNS lookup entirely and establishes a direct connection to the server.

Step-by-Step Configuration

1. Copy the client's *.lic file from the license folder and paste it onto your Desktop.

   Note: Windows access permissions prevent editing files directly inside the license directory. You must edit the file on your Desktop first, then copy and paste it back to overwrite the original.

2. Open the Desktop copy of the *.lic file using Notepad.

3. Replace the server hostname with the server's static IP address (e.g., 10.101.102.103), using the following format:

   Plaintext

   #LSHOST=10.101.102.103
   HOST 10.101.102.103
   

4. Save the changes, then copy and paste the updated file back into the application's license folder (confirming the prompt to overwrite the existing file).

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