There are a couple of reasons you might receive the Invalid Profile error while enrolling Apple devices. This article lists a few of the causes and solutions to help with troubleshooting.
Problem: Your TechPilot account is out of licenses for that operating system.
To diagnose: In Control Tower go to the Dashboard and look in the box entitled "Licences Used". The bar graph will show you total licenses (blue) and licenses used (red).
Solution: Contact your TechPilot Sales Engineer to purchase more licenses OR contact support and have us move available licenses from one OS to another OS.
Problem: Apple Enrollment Profile needs to be refreshed.
Description: Apple purges old enrollment profiles from their servers every now and then.
Solution: In Control Tower > Settings > Apple DEP > Click on the name of the DEP account > DEP Tab > Update DEP Settings at the bottom of the tab. Wait for the sync time to change.
In either case, if you had any devices that you tried to enroll and received the download profile failed, you will need to hook these devices to iTunes or Configurator and perform a "Restore as New". https://support.apple.com/en-us/HT201252