Error Message--Unable to write Signal File

Nov 1, 2014


The following error message is issued when attempting to start an analysis: 

Error: Unable to write signal file



When launching from Pro/Engineer or CATIA v5, Autodesk® Simulation CFD uses a temporary file (the “signal” file) to record the launch and meshing state. This error means that this file could not be saved. Without this file, meshing cannot occur.

To resolve this issue: 

The following work-around has shown to work for many cases:

1. Close Autodesk® Simulation CFD and the CAD system, and reboot the computer.

2. Check licensing. On a client (network license), ensure that the license file has the following form (port# is optional)

server servername 0 port#


3. If launching from Pro/Engineer, ensure that the working directory is set prior to opening the CAD model.

4. Check the working directory and the analysis name. There should not be any punctuation characters such as "#," "$," "@," "%," or "&"


Simulation CFD