Description

While not common, the Windows firewall on an Ansys client computer can block or prevent the program from running properly. This is most commonly seen when using fluent and it's related MPI's that utilize the network. This can also occur on machines utilizing RSM. This guide will help you identify if the Windows Firewall is causing the issue and what applications/executables need to be allowed.

An application can be blocked by the Windows firewall if when being opened, you are prompted to allow it through the firewall and select Cancel, or if you are not a local administrator on your computer.

Note - not allowing an application through the firewall doesn't always produce errors.  It all depends on what application is being used. 

Solution

Step #1 - Rule Out the Firewall as the Cause

1. Windows Search > search for and open Windows Defender Firewall. 
2. Click Turn Windows defender firewall on or off.
3. In all sections, select Turn off Windows Defender Firewall (not recommended)
4. Attempt to reproduce the error.
5. If you can still reproduce the error, the Windows Firewall is not the cause.
6. If you cannot reproduce the error, the Windows Firewall is the cause.  Proceed to Step#1 to identify what application is being blocked and allow it.
7. Re-enable the Windows Firewall

Step #2 - Identify & Allow the Blocked Ansys Application

1. Windows Search > search for and open Windows Defender Firewall with Advanced Security
2. On the left, select Inbound Rules
3. Click the Program column to sort by the program path
4. Check the list of rules for any blocked executables starting with the following paths:
   • C:\Program Files\ANSYS Inc
   • C:\Program Files\AnsysEM
   • Examples of Ansys executables that are being blocked:
5. Right Click on the rule > Properties > select Allow the Connection > select OK