No, there will be no problems arising from entering multiple W-2's.

To enter a W-2, follow the steps below.

• Sign into TurboTax online
• Click Take me to my return
• Choose the Federal tab if you are not already there
  
• On the Income and Expenses tab, you can click Add/Edit next to the W-2 section. 
  
• You can then add another W-2, by clicking the option Add a W-2.