I see that this is an older post - I too had the same issues with installing the ExpressVPN Tap adapter and I needed a 'digitally signed' driver to get the TAP Adapter to function properly. I contacted Express VPN support and they directed to me to install an older version of the ExpressVPN Software.
I don't know about you - but I like the latest and greatest software on my machine and I didn't want to settle for an older version - so I set about working out this issue. I am going to attach a picture so you can see that I worked it out. I am NOT going to mention the resolution unless you remark that you still want / need it. If you have it worked out and don't feel like messing with it - No worries - I just don't want to waste my time creating a tutorial when it's not needed.
Tap Windows Adapter V9 Install
Value data=TAP-Windows Adapter V9 disable and enable TAP-Windows Adapter V9 in device manager network adapters to reinitialize the driver with the newly added ComponentId Users with Kaspersky Internet Security install might still have issues after following this tutorial. The logs show that the TAP-windows driver is not installed on my machine. When trying to add tap-windows-9.9.23 or 9.21.1 the installation fails. I have tried on cmd prompt from the Windows 10 app as well and get the following error: C: Program Files TAP-Windows binrem Add a new TAP virtual ethernet adapter.
Reinstall Tap Driver Windows 10 Hp
Take a look at the picture - and you can see that I have all the ingredients for a 'digitally signed' driver error, but it's working like a charm. Let me know if you'd like the work-around - It's relatively simple to do.