I get a "SSL_do_handshake returned error"

  • Updated

After accessing the web interface of the MLS I get an "SSL_do_handshake returned error".

We can offer five possibilities to solve this issue:

1. Whitelist https://id.maxon.net in your proxy settings

In case your company uses a proxy for internet connections, it might be possible that you have to whitelist the following domains inside your network:

2. Add https://id.maxon.net to Internet Explorers trusted sites (windows only)

Open the Internet Explorer (not Edge), and use the cogwheel symbol in the top right corner to choose and open the Internet options.

On “Security” click on “Trusted sites” and add the sites https://my.maxon.net and https://id.maxon.net

3. Try to reset the MLS 21 to default settings and start from scratch

  • First, stop the MLS service.
  • Open the folder "C:\ProgramData\Maxon\License Server" (Windows) or "[HDD]:Library:Application Support:Maxon:License Server" (macOS) and delete it.
  • If not done already, load and install the latest MLS installation from our website: https://www.maxon.net/en/downloads
  • Configure the newly started MLS 21 service to your needs.

4. Add a current certificate to the MLS by Hand

  • Stop the Maxon License Server (MLS) service.
  • Open the folder “C:\Program Files\Maxon License Server\resource\ssl" (Windows) or "Applications:Maxon License Server:resource:ssl" (macOS) and open the file "cacert.pem" using a text editor.
  • Access https://id.maxon.net via Firefox.
  • Click on the lock symbol next to the URL.
  • In the section "Connection Secure" click on the Arrow button on the right (Connection Details).
  • Next on "More Information" at the bottom.
  • A pop-up window opens.
  • Click on the button "View Certificate".
  • A new browser tab opens, further down on that tab next to "Download" click on PEM (chain) / save it as a text file / open it with the editor right away.
  • Copy the text blocks to the end of your existing cacert.pem and save it.
  • Restart the MLS service.

5. Remove the installation

Remove the current installation by using the uninstaller from the programs installation folder and install from scratch, using the latest Installer from our website:

https://www.maxon.net/en/downloads - MLS is under the latest Cinema 4D version.


6. Install the Microsoft Edge browser (Windows Server only)


Windows Server does not include Microsoft Edge by default and we've found that in the case of the above-mentioned error, installing Microsoft Edge can sometimes resolve the issue on Windows Server.


Here is a link to download the Microsoft Edge installer:




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