Try closing the TurboTax program, then close all open programs. Re-start your computer and then open the TurboTax software again and see if you can enter the license code.
You may also try a copy and paste of the code, use Ctrl+C to copy and Ctrl+V to paste
If still unable to enter the code, contact TurboTax support for assistance.
See this TurboTax support FAQ for contacting support - https://ttlc.intuit.com/community/using-turbotax/help/what-is-the-turbotax-phone-number/00/25632
Support can also be reached by messaging them on these pages https://www.facebook.com/turbotax/ and https://twitter.com/TeamTurboTax
