I got the same email that offered a free upgrade to LE. I downloaded it and installed it fine until it asked for the license. I put the license in and it recognizes it as LE. However, it also says there are no licenses to upgrade. I plugged in the USB dongle with my other Steinberg licenses but it still says there is nothing to upgrade.
The confusion for me is the email says there is a free version waiting and has an option to do a full install. It sounds like the original poster has a similar licensing issue and it makes me wonder - if we don’t actually have licenses to upgrade, then why did we get the email?