Nichole Choice, we didn't TEs in PDF format for these editions. There is an option to get the e-text. The first time you do it, you will be walked through the process of creating a login for the VitalSource Bookshelf. I miss the PDFs also, but this is what they gave us.
Why isn't there a digital Teacher's Edition on my TTO for 8th grade Pre-Algebra (3rd Edition)?
Two possible things could have happened: 1) TTO logged you out automatically after a period of time. In such a case, you can log back in and have your usual access. 2) Your administrator (or whomever has been designated to handle the TTO account at your school) has not assigned those courses to you. He/she should be able to log in and do that; you'll just have to bring it to that person's attention.
I am having the same issue. I teach 5th grade English and Heritage Studies and I do not have access to these classes.