Upgrading the ADFS Adapter is not straight forward, though the readme notes for the upgrade make no mention of issues! To upgrade MFA Server 6.3.1 to 7 (so you can remove .NET 2 as a requirement, as that goes out of support soon) then you need to download the MFA installer to each MFA server… Continue reading ADFS Adapter Issues With Upgrading MFA 6.3.1 to Version 7