I checked my recent updates and found what turned out to be the culprit: KB5018410. This was all the confirmation I needed that the Windows Update was the source of this newfound error. At least until his FortiClient VPN required a reboot (probably because it detected a pending Windows Update).at which point Windows installed updates.and following said reboot.he was also unable to connect. I then checked with a colleague to see if he could connect to their VPN. I reached out to our client to see if they had made any recent changes to their VPN server. Confirm No Changes Made to the VPN Server Satisfied there was nothing more I could do with my VPN client utility, I moved on to the next troubleshooting step. I ran the Online Updater utility, but all it did was confirm that, yes, I did have the latest version of FortiClient VPN:

So, I went to the FortiClient VPN download page and downloaded their automatic updater. It doesn't even say when it performed its last update check. It said 'latest version', but for all I know it's been saying that for months. (-5) Checking FortiClient VPN for Updatesīefore uninstalling Windows security updates, I checked to make sure I had the latest version of the FortiClient VPN client utility. The server you want to connect to requests identification, please choose a certificate and try again.

I got the following warning message when trying to connect to one of my clients via the FortiClient VPN: Warning

Forticlient download