The NADA MarketValues application iOS version downloads all data files in the background and unzips and processes those files once a month when the app is turned on and there is a new data file available.
If the user attempts to scan a VIN before the data file update has been completely downloaded and unzipped, the app will freeze.
The quality of the data network connectivity (cellular network vs. WiFi, etc.) affects the amount of time required to download the data file update. So best practice after the first of the month is to launch the app at a location that has excellent cellular or WiFi connectivity, and allow enough time for the current month's data file to be downloaded and unzipped, before attempting to scan a VIN or do a bookout.
The data file will not download again until the following month when an updated data file will be sensed and downloaded when the app is launched.
To recover from the frozen app, turn your wireless device off, and then on again. Then relaunch the NADA MarketValues app and allow enough time for the data download to be completed before attempting to scan a VIN or bookout a vehicle.