If you expected a 1042-S but do not have one in GLACIER, most likely you did not take the treaty through Georgia Tech in 2015. However, you can still receive the treaty benefit through your tax return. If you use Sprintax, the program will know from your other forms that you haven't yet taken the treaty and (if you are eligible) Sprintax will make the appropriate adjustments to your tax refund. You do not need a 1042-S to claim a treaty benefit, it is simply a form for reporting a benefit that has already been claimed.
Both resident and nonresident aliens for tax purposes who already claimed treaties in 2015, as well as all those students who are nonresident aliens for tax purposes receiving scholarships greater than tuition, will use a form 1042-S to complete their tax return. 1042-S forms were released on February 12, 2016. Recipients received an email from GLACIER when the form was ready.