ERROR

When you launch Fluent from Ansys Workbench with Use Remote Linux Nodes enabled, Fluent fails to start Node 0 on the remote Linux system and shows the error below. You cannot run the simulation.

Connected License Server List: 1055@xxxxxxxx
Host spawning Node 0 on Machine "xxx.xxx.xxx.xx" (lnamd64).
Host waiting for connection from Node 0 at "xxx.xxx.xxx.xx:xxxxx"

Access is Denied

Check your network connections and remote shell configuration.
If you are on a slow network, running cache flush, or running through a scheduler like lsf or sge, you may choose to wait.
Type Crtl-C to interrupt.

Software & Version

Ansys Workbench and Fluent 2026 R1 (v261) on Windows.
*This documented instance of this error occurred in this version but is not necessarily limited to this version.

Description/Cause

You will usually also see:

• The same remote Linux node works when you launch from the Standalone Fluent Launcher on the same Windows computer.
• The same workflow works from Workbench 2025 R1.
• Workbench 2026 R1 may have worked before, then stopped.
• Licensing works: the license check succeeds and Ansys Licensing Settings shows no errors.
• SSH to the Linux node works from the command line. For example, Test-NetConnection <linux-node> -Port 22 returns TcpTestSucceeded : True.
• The failure happens on more than one Windows computer, so it points to the Workbench launch environment, not the network or firewall.

Workbench starts Fluent from the "Start in" folder of its shortcut. If that folder resolves to C:\WINDOWS\system32, the Fluent Launcher shows C:\WINDOWS\system32 as the Working Directory.

In 2026 R1, the cmd.exe process that runs the remote spawn command writes a temporary Message Passing Interface (MPI) output file (flmpi-<number>.txt) to the working directory. A Microsoft Sysinternals Process Monitor capture showed a cmd.exe command line similar to:

cmd.exe /c ssh -l <user> <linux-node> /<path>/v261/fluent/bin/fluent 3ddp -r26.1.0 -pdefault -node -t1 -mport <ip>:<ip>:<port>:0 > flmpi-<number>.txt 2>&1

A standard user does not have write permission to C:\WINDOWS\system32, so Windows denies the write and the remote node never starts. In the documented instance, the shortcut's "Start in" field was set to %HOMEDRIVE%%HOMEPATH%, which resolved to C:\WINDOWS\system32 instead of the user profile folder.

*The cause(s)/solution(s) we identified in this documented instance may not be the only cause(s)/solution(s) for this error.

Solution

1. Check the Fluent Working Directory

1. Launch Fluent from Workbench 2026 R1, then select the Home tab of the Fluent Launcher.
2. Check the "Working Directory" field. If it shows C:\WINDOWS\system32, this cause applies, so continue to the next task. If it shows your user profile folder, this documented cause does not apply.
   
   Note: In the Standalone Fluent Launcher, the same field shows the user profile folder, for example C:\Users\<username>. Replace <username> with your Windows username.

2. Change the Workbench Shortcut "Start In" Folder

1. Close all Ansys applications.
2. Open the Start menu, right-click Workbench 2026 R1, and select Open file location.
3. Right-click the Workbench 2026 R1 shortcut and select Properties.
4. On the Shortcut tab, check the Start in field. If it is set to C:\Windows\System32 or %HOMEDRIVE%%HOMEPATH%, change it to a folder you can write to, such as your user profile folder: %USERPROFILE%
5. Click OK.
   
   Note: If Windows asks for administrator permission, have your IT team make the change.

3. Verify the Fix Worked

1. Launch Workbench from the updated shortcut, then open Fluent on the remote Linux nodes again.
2. On the Home tab of the Fluent Launcher, check that "Working Directory" shows your user profile folder, for example C:\Users\<username>.
3. Check that Fluent starts on the remote nodes without the error in the ERROR section above. If it does, you're done.