It depends. TurboTax allows uploads for Form W-2, but it can also be entered manually. It would not necessarily be the only reason for a rejected filing.
Please see this article for more information about the most common reasons and how to fix the returns: How do I fix a rejected return?
You may have to paper file. Click this article for details on how to do that: How to change from efile to paper file? For Online; For CD/Download
