• Humanoid posted an update 3 years, 7 months ago

    Hi, Does anyone know how to open the STL files in Windows 7? I keep getting a ‘Certificate Trust List’ error when I try to open the downloaded file? Does anyone know what this means?

    • This answer is in the Forum:
      You are using a Windows computer and the default file extension for STL is “Certification Trust List”. It’s a Windows thing. If you click directly on an STL file, you will get this message. You need to right click on an STL file and change the file association to whatever program you are using to view your STL files. This will not affect anything else.

      • Thanks very much. Hopefully my new 3D printer will have the appropriate software to open these files when it arrives.

        • Your 3D printer software will be able to read the STL files and convert them to a format that the 3D printer can use (g-code). But if you want to change them, the you need a 3D modeling software. I and many other people use Blender. It’s open source and free to use. You can find it here: https://www.blender.org/ After installing it you also need to activate the stl plugin to be able to import / export stl files. You can find many other alternatives too. Google “free 3D modeling software”.