SOLIDWORKS SolidNetWork License Manager Troubleshooting (SNL)

Article by Scott Durksen, CSWE updated April 14, 2021


A SOLIDWORKS Network License requires a network connection between the server and client machines.  The server runs the SolidNetWork License Manager service and client machines must verify a connection and available licenses from the server before SOLIDWORKS will open.  Communication errors are commonly found on first setting up a network license or if there are changes to the network.

SOLIDWORKS SolidNetWork Connection Errors

Here are a few possible error messages that may be seen on a client machine when trying to open SOLIDWORKS:

  • Cannot connect to license server
Could not obtain a license for SOLIDWORKS Standard

Cannot connect to license server

  • Server node is down or not responding
Server node is down or not responding

Server node is down or not responding

  • Could not get information from this server

Could not get information from this server



The SolidNetWork License Manager needs to be installed, activated and started on the server.  The major version needs to be the same or newer than SOLIDWORKS running on the client machines.  It is backwards compatible so you should always upgrade the License Manager before SOLIDWORKS.  For example you can use a 2019 License Manager while running SOLIDWORKS 2018.

After any upgrade to the License Manager, you must reactivate to obtain the latest license version.

Service Started

Verify that the SolidNetWork License Manager service is running.  Open the License Manager and click ‘Start’ if applicable.  You can also check Windows Services to verify the service has been started and set to Automatic startup.

SOLIDWORKS SolidNetWork License Manager Start

SOLIDWORKS SolidNetWork License Manager Service

Firewall Settings

The most common source of communication errors are due to firewalls blocking the required ports.  If you do have firewalls setup on your network, you will need to select the option that ‘A firewall is in use on this server‘ while activating.

IMPORTANT: Contact your IT department to ensure proper Firewall settings are applied

This switches the License Manager to use a static vendor daemon port in order to specify the specific port in the firewall.  By default the License Manager uses TCP ports 25734 and 25735.  These can be changed if required.

To access these options again, you can go through the same reactivation process.

SOLIDWORKS SolidNetWork License Manager Ports

SOLIDWORKS SolidNetWork License Manager Ports

Communication on ports 25734 and 25735 must be allowable through the firewall for Inbound and Outbound communication.  For the default Windows firewall, the follow process can be taken.

  1. Go to Windows Control Panel > Windows Firewall
  2. Select Advanced settings in the left panel
  3. Select Inbound Rules in the left pane and choose New Rule
  4. Choose Port and specify TCP ports 25734 and 25735
  5. This needs to be set to Allow the connection
  6. Choose the appropriate profiles from Domain, Private, Public
    NOTE: Allowing access through the Public profile is not recommended. Verify your network settings to determine required access.  Opening a port within the Public profile is at your own risk and should be reviewed and approved by your IT.
  7. Give a descriptive name for the rule such as “SolidNetWork License Manager Ports” and Finish
  8. Select Outbound Rules in the left pane and choose New Rule
  9. Follow the same steps 4-7 to allow outbound connection for ports 25734 and 25735
Windows Firewall Rules

Windows Firewall Rules


Though not typically required with the default Windows Firewall, you may need to apply a rule to allow connection for programs lmgrd.exe and sw_d.exe.  By default these programs are located under C:\Program Files (x86)\SolidWorks SolidNetWork License Manager.





With the default Windows firewall settings the client machine should be able to accept connectivity through both ports 25734 and 25735, as it is seen as a response to outbound communication from the server.

NOTE: If communication is still failing through these ports (see Telnet Test below), contact your IT department as changes may have been introduced to the firewall settings preventing inbound/outbound communication on the client.

Server Location

Verify the SolidNetWork License Manager Client application is pointing to the correct server.  This application is found under Start > SOLIDWORKS Tools > SolidNetWork License Manager Client.  On the Server List tab, add the appropriate port and server name.  Ensure only one server is listed unless you have multiple servers hosting separate licenses.

NOTE: When you add a new server name to the list, click OK and go back into the License Manager to verify the new server name is still listed.  If it doesn’t stick, you may need to run the License Manager Client application as an administrator.  Right-click on the application in the Start menu on click Run as Administrator

SOLIDWORKS SolidNetWork License Manager Client

SOLIDWORKS SolidNetWork License Manager Client

You can also test entering the server IP address instead of the server name to see if there is an issue with name resolution.

If you still receive errors on opening SOLIDWORKS, there are several tests you can perform to verify the connection is valid.

Ping Test

The Ping test verifies that you have access to the server over the network.  This will also give you an indication of the speed of connection from the response time (latency).  If the test fails, you will need to check your network connection on both machines.

  1. Open the Windows Command Prompt (click Start and type CMD)
  2. Type in ping server_name (where “server_name” is the name of your server or the IP address)
  3. It should give a response that 4 packets were sent and 4 were received with 0% loss to verify you have a connection
Windows Ping Test

Windows Ping Test

The speed in milliseconds will be given to determine the latency.  This should be a low as possible.  If it shows more than 100ms, this indicates a very slow connection and may fail to obtain a license due to a default timeout.  Have your IT troubleshoot the slow performance of the network.

Telnet Test

The Telnet test allows you to verify that ports 25734 and 25735 have been opened properly.  This can be performed two ways.

    1. Click Start > type powershell and open the app
    2. Type tnc yourservername -port 25734 (where ‘yourservername’ is the name of your server hosting the License Manager)
    3. TcpTestSucceeded will show True if communication is successful.  If it states False, have your IT assist in troubleshooting the firewall port settings.
Command Prompt

Review our article How To Perform a Telnet Test

Connectivity Tool

Although typically used to troubleshoot SOLIDWORKS PDM connections, the Connectivity Test Tool can be used to test for the SNL Server connection only.  To find out where the tool can be downloaded, read our blog article SOLIDWORKS PDM Connectivity Test Tool

SOLIDWORKS Connectivity Test Tool

SOLIDWORKS Connectivity Test Tool

Related Links

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Scott Durksen, CSWE

Scott is a SOLIDWORKS Elite Applications Engineer and is based in our Dartmouth, Nova Scotia office.