If your Training Manager has sent you an invite and you see the above error, this means you have already accepted the invite. You cannot use an invite link to login after you've clicked on it/used it. You must go directly to the website you were invited to and login (ex. danatec.com).
If your Training Manager originally sent the invite to your email, your email is your username. Did you get an invite to the course to your cell phone? Your username is your 10 digit cell number. Even if you are using a computer and the invite was sent to your cell, your cell phone number is still your username regardless of which device you are using.
You should have been prompted to create a password when you originally accepted the invite. If you do not recall what this is, or didn't set one up, go to the login page > forgot password > enter email or phone on file > reset password via email or SMS > go to login page > login.