FortiClient and macOS Big Sur – SSL top, IPsec flop

Spoiler Alert! – Since the release of macOS 11.0 aka Big Sur, your FortiClient VPN might not be working as expected anymore if you have already upgraded.

There’s a chance you might not have noticed it, in the case that you’re using SSL VPN only in your environment. But as soon as you also have IPsec tunnels you’d like to use, you might find yourself with a successfully established tunnel, but no traffic is reaching your remote end.

Reason is a legacy kernel extension which was still used by FortiClient ≤v.6.4.1. This kernel extension was only loaded for IPsec connections but is now prohibited to run under macOS Big Sur.

Unfortunately there’s no notification by the FortiClient software, informing you of this. Also there’s no statement yet on the official website. But numerous users reported this behaviour throughout Apple and Fortinet support forums, as well as on

So far we can only tell you to await the promised release of FortiClient V6.4.3 that should address the issue. There’s no specific release date published yet, but we’ll update this article as soon as this is the case!

So in the meantime, please hold back yourself with a hasty upgrade to Apple’s latest OS.

Update Januar 2020: Even though FortiClient v6.4.2 is not officially supporting BigSur, it seems that the IPsec issue has been solved in this release! So if you’ve already upgraded your Mac to BigSur, go and update your FortiClient to 6.4.2 as well.

2 thoughts on “FortiClient and macOS Big Sur – SSL top, IPsec flop

  1. TP Reply

    Hi, I keep getting connection error 130 when trying to connect with FortiClient on MacOS BigSur. Is the issue still not resolved? How can I resolve the issue, as FortiClient was working fine on Catalina…?

    • vla Reply

      Dear Reader
      Thank you for reading and commenting our blog.
      We are not providing support over our blog. Please get in touch with your reseller if your have any further questions regarding this issue.
      I’ve had more than one case lately, where a reinstallation of the latest FortiClient for macOS (which is 6.4.3) solved the problem. Please note, that you must reboot your mac after removing the software and once again after installing the software again. This problem is caused by the new macOS security dialogues, which did not work as expected (documented under But as per my experiences, removing and reinstalling the software is the easiest way to fix it.
      Kind regards,
      The Boll Engineering Tech team

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