Hi,
Welcome to Pix4D Community!
Is it possible that this has happened because you lost your internet connection while doing the mission? If you are doing the mission in a remote area where you are at risk of losing the internet connection, then I recommend doing the mission with the settings of an offline mission. You can read more about this option in the next post. Offline mission - #7 by Gael
Please let us know more details about your workflow if you need further assistance.
Have a very nice day.
Best regards