Why does turbotax not allow me to enter a 1098-t in my dependants name? add a student does not work.

Try this and see if this helps.  I understand some steps may be repetitive but it should fix whatever is going on and let proceed to prepare your return. 

1. Go to the input section for the 1098-T. 
2. You will probably skip to the section titled books and supplies.  Just continue as you probably will not be able to enter any information here.  Just continue through the screen. 
3. Do Not enter any scholarship amounts when it asks if the scholarship is listed in Box 5 of the 1098-T.  We want to avoid potentially doubling up any input already made.  Hit continue instead. 
4. Continue through all the screens. 
5. You may get a message which says you can't maximize because there are no expenses.  Just select continue until it takes you back to the Wages & Income screen. 
6. Now, Go back into the "Education Credit" section. 
7. Select "Edit" next to the student. 
8. It will ask you if you had an education credit and show you the summary. 
9. Select "Edit" to the right of Tuition. 
10. It will ask you if you received a 1098-T.  Select Yes and continue. 
11. The next page should show you your input on the 1098-T. 
12. Continue through the screens 

This should eventually take you to the screen showing which deduction you can take. 

After you pass this screen, run a review. 

The issue should resolve itself allowing you to continue preparing your return.