There are no known issues, but if you're using TurboTax Online, try clearing your browser's cache and deleting your cookies, then see if you can continue where you left off. See the TurboTax Help articles How to clear your cache and How do I delete cookies? for guidance.
If you're using the desktop edition, there are a few fixes you might try. See if the guidance in the TurboTax Help article Troubleshoot TurboTax Desktop for Windows issues will help with your issue.