SimWorks installation troubleshooting

SimWorks installation troubleshooting

Please find below a collection of the most common issues you can encounter while installing SimWorks and the relevant solution.

Cannot download the installer - manual installation guide

Depending on your system settings and in particular your Antivirus settings you could not be able to download the installer. The installer is a lightweight .exe file (1.3Mb) which connects with our website, downloads the SimWorks source file, which is a 2.2 Gb file and installs it. The file itself is time stamped and certified, please see our SimWorks security page to have more info about our security policy and certifications. Sometimes some antivirus recognise it as malaware and prevent the user from downloading the file, it is possible to add SimWorks as an exception.

Alternatively you can complete the following points to install SimWorks manually: 

1) download SimWorks from source here, this is around 400Mb and contains the main SimWorks executable. Depending from your internet connection you may need a free download manager of your choice to download it successfully. Once the download is completed you just need to unzip it, you can use 7zip or any free tool of your choice. 

2) download the SimWorks main Linux distribution here, this is a 1.8Gb which contains a complete Linux environment for Windows including OpenFOAM. Again unzip it and copy the resulting file inside the SimWorks install folder and ThirdParty/Linux:

Copy the Linux install file inside SimWorks/ThirdParty/Linux

3) type Powershell in the cmd line of windows, right click on it and select Open as administrator

Open Powershell as administrator

4) Enable WSL by typing in PowerShell: dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart


5) Reboot the PC

6) Start SimWorks by clicking on SimWorks.exe in the installation folder and follow the instructions on screen

Windows 10 and antivirus warning messages

Windows 10 can occasionally show warning messages after the SimWorks download is completed, just click on More info in the first page and then on the Run anyway button:

SimWorks comes with a Code Signing certificate, therefore you should no longer see these warning message. If you still get warnings please let us know by contacting us.

Similarly, your antivirus might detect potential threats in our installer executable but you can check the validity of our executables on these websites:

For reference please see the SimWorks security guide

Debian install error

Sometimes the setup step can take very long to complete, this is because Debian (a Linux distribution) will need to be installed in WSL. The size of the install is around 4.5 Gb and all the files need to be copied across.

Debian install step

To check the progress of the install just open the SimWorks –> ThirdParty –> Linux folder inside your install directory:

You will find the DebianISimOFv2006 file (or any newer version) which is the source of the Debian distribution and the rootfs and temp directories, which are the install directories. The latter two directories will be progressively populated with the Debian files and will increase in size until the install is completed.

The whole process can take from 15mins on an SSD machine to 40mins on a conventional HD machine, if the process is terminated it will be restarted at the following SimWorks install. So if you have issues just restart SimWorks and follow the instruction to attempt a new install. If you still have problems please contact us and we will be happy to help.

Fatal error on first run

If SimWorks fails to run showing the fatal error message below, it is likely that one of our libraries fails due to an issue when decoding strings.

A possible solution is to update the encoding key in one of our settings files. Please follow the procedure below.

Open a Windows Powershell and type the command:


This will display the system settings related to text encoding. Below is an example of the output:

Please check the HeaderName entry in your output and if this is different from Windows-1252 or ISO-8859-1, you can try to update the file isim_user.cfg that you will find inside the Scripts folder in the SimWorks installation directory. For example:

Please open the file with Notepad by navigating to the path above. In order to see the isim_user.cfg file, you must select All Files as highlighted in the red box below:

Once the file is open, please change the content in the encoding tag (see the highlighted text in the picture below) to the value corresponding to HeaderName of your system.

After the change, save the file, close Notepad and try to restart SimWorks. If you still get the fatal error message, please contact us sending a snapshot of your Windows encoding settings as shown above.

Transferring error during install

If the internet connection drops out during install the installer will show the status as TransientError rather than the usual Transferring and the download process will be hanging:

Please do not stop or kill the installer. Simply restore your internet connection: the download will resume automatically and the install process can be completed successfully. 

Install after update to Windows 11

After updating your system from Windows 10 to Windows 11 you might encounter issues during the installation of the Linux distribution in WSL.

For example:

To resolve this, you might need to re-enable the virtualisation on your machine. To do so, we recommend to follow the official guide:


Try the free version of SimWorks or contact us to find out more