When upgrading the VIP ADFS integration, the VIP ADFS plugin fails to execute during 2FA. This is evidenced by the lack of a log file being generated due to the IPAuthenticationProviderWindowsAccountName not executing.
An error occurred loading an authentication provider. Fix configuration errors using PowerShell cmdlets and restart the Federation Service.
Identifier: VIPAuthenticationProviderWindowsAccountName
Context: Proxy device TLS pipeline. PublicKeyToken=xxxxxxxxxx could not be loaded. Could not load file or assembly 'VIPAuthenticationProviderWindowsAccountName,
In a server farm, the AD ADFS records track the functioning version of the plugin. Hence, the last successful ADFS record is seen across the farm and prevents later versions from starting properly.
Upgrade all ADFS servers (Server 2012, Server 2016, etc) in the farm to share the same VIP ADFS plugin version. The lastest version can be downloaded from VIP Manager. (The version is determined by the version.txt file located in the same folder as the installer)