Two coworkers have had this problem so far.
Make account - Verify account
So far so good...
Try to log into TV12 on PC
account not found
Login to Teamviewer website with the same account, works.
Try to log in on PC again, get this account is not verified message.
Send email, click on link, successfully verify the account again.
Try to log into PC
over and over and over again.
This is really annoying and Teamviewer really does need to fix this.