Error Message—Connection and Communication Errors

Issue

After clicking the Start button on the Solve dialog, one of the following error messages appears and the startup process stops:

Error Message: "Could not start solver"

Error Message: "Unable to start solver process"

Error Message: "Unable to start solver process: Mesher exited during startup"

Error Message: "Unable to start solver process: Solver exited during startup"

Error Message: "Unable to Copy files to Solver"

Error Message: "Connection Error"

Error Message: "Unable to copy files to Solver"

Error Message: "Unable to attach to Solver"

Error Message: "Unable to attach to Mesher"

Error Message: "Unable to start Mesher"

Autodesk® Simulation CFD is built upon a client-server architecture, and communication between several different modules is managed by the Server Manager. Communication between these modules is essential for proper operation of Autodesk® Simulation CFD. If messaging between these modules is blocked, it is not possible to run a simulation.

These are the primary causes of these message:

1. The communication server (CFdserv.exe) is not running.

2. Communication issues due to system-level issues.  These include:

• Firewall that is blocking communications
• Insufficient permissions
• Network issues (faulty, slow, or a down network)

Solution

Perform the following sequence:

1. Use the Task Manager to verify that CFdserv is running.
2. If CFdserv is not running, start ServMan.exe, click Stop, Uninstall, and Install.
3. Check Task Manager again to verify that CFdServ is running.
4. If CFdserv is not running, open Servman.exe, and click Stop and Uninstall. Open the CFdesign installation folder, and delete the contents of the Analyze sub-directory. Click the Install button on Servman.exe.
5. If CFdserv is still not running, open the Solver_Manager.log file in the Analyze sub-folder. If a message indicates that a port is unavailable, reboot the machine, and check this file again.

If running on a Remote or HPC machine, perform the steps described above on the remote computer. Also ensure that the same version of Autodesk® Simulation CFD is installed on the local and remote computers.

Some Additional Things to Try: 

1. If using Pro/E:

• Ensure that the working directory (in Pro/E) is set to the same folder containing the analysis.
• Make sure Intralink users are running Autodesk® Simulation CFD locally.

2. Check the permissions of your personal login account. The following are the minimum requirements:

• Read access to the Autodesk® Simulation CFD installation folder.
• Read/Write access to the working directory containing the design study.

3. Check the permissions of the account that cfdserv is running under (System, if local). The following are the minimum requirements:

• Read access to the Autodesk® Simulation CFD installation folder
• Read/Write access to the Analyze sub-folder
• Read/Write access to the working directory containing the design study.

4. Check for adequate disk space and RAM

5. Check the Analyze sub-folder.

• Delete legacy files.

6. Check the file and directory names:

• Only letters, numbers, and underscores should be used.
• Remove "odd" characters such as "&", "%", "@", “!”, and commas.

7. Ensure that the firewall will allow communication between the Autodesk® Simulation CFD Server (cfdserv) and the other modules (Solver, Mesher).

Modify the settings on your firewall to make exceptions for the following processes. This allows unimpeded communication across the Firewall between these modules and the Server Manager:

• CFdesign.exe
• cfdcalc.exe
• cfdserv.exe
• mesher.exe