Cannot log into AVD with encore username

First, make sure you are using the correct spelling for the username.  Encore usernames are typically something like "FCIuser@coreasp.com" and the password is a long string of letters and number.  If you are using the correct username/password and still cannot log into encore AVD, and get an error that mentions the Freehold Cartage tennant, you can subscribe with URL with the following

https://rdweb.wvd.microsoft.com/api/arm/feeddiscovery