I am trying to active the legacy license within a Teamviewer account in the management console under Edit Profile, but it is not accepting the old license.
Thank you for your message.
I recommend you to double-check if you have entered the correct license key. Please make sure to use the first license key that is shown on your invoice.
You will find all the information you need in our Knowledge Base article here: My license key doesn't work, what can I do?
I hope this could fix the issue.