Make sure that you have entered your driver's license number and use any numbers and/or letters and no spaces in the beginning or in between, or at the end, and no special characters.
Keep in mind this is an added security measure, but for most states your return can be filed and will process without your driver's license number. If this keeps happening try taking it out completely.
https://ttlc.intuit.com/questions/2940013-why-are-you-asking-for-my-driver-s-license-or-state-id?jum...