We have just released a new fix for Khans of Tarkir for Decked Drafter. Kindly update your database to prevent any crashing issues. If you are unable to start your app after the update, you might need to delete and reinstall the app.
Please accept my sincere apologies for the inconvenience -- it was due to the "multiple lands of the same name" support added in Decked Builder being ported over to Drafter, and Drafter being unable to support that in it's current iteration.
- Tan Thor Jen