When experiencing problems with TurboTax online it is often due to a corrupted browser cache. You may also need to delete "cookies" as well. The TurboTax FAQ's below explain this and has links to help you clear your cache for the most popular browsers and delete cookies.
Please contact customer support at: https://support.turbotax.intuit.com/contact/ if you need additional assistance. (note: If you are using Free Edition you will need to upgrade to Plus for product support.)
https://ttlc.intuit.com/replies/3302272
https://ttlc.intuit.com/replies/3301745