RubberDave

Just an update to this to give a bit more info on where the issue may lie, having had he same problem again on a new laptop. If I went into HX Edit, it had the option to authorize computer, but it didn't do anything when clicked, and this is all despite the license manager saying the computer *was* authorized. I was signed in but HX Edit thought it wasn't authorized. I went into the license manager and deauthorized it so I could go into HX edit to authorize it, and only then did the option now say 'Deauthorize Computer' without changing anything else, so it was now automatically authorized and Native now works, and my computer still shows as active in my active devices on the site. It appears the bug is in the license manager somewhere. TL:DR Deathorize if authorized using the license manager. Sign in using HX Edit and let that authorize the computer.

I was having this issue today. Line 6 License Manager was showing my device as authorized, but it would not authenticate when trying to use it in Reaper. I tried all the usual troubleshooting steps. Restart, log out and back in, uninstall, reinstall, install older version etc... The solution: Download HX EDIT and sign in to there. Doesn't matter that I didn't have the pedal plugged in. As soon as I signed into HX Edit, Native started working.

EDIT: - Looks like this has been fixed. I had to restart my PC for it to actually take effect despite the version number showing v3.15