USB, Wifi, Flight Calibration, Power Failure, or Human Error Calibration.
Did you format..? This resolves 99% of collection failures. Start with a formatted USB. Especially if you had a failure event prior to your current collection. See https://learn.rockrobotic.com/reformatting-your-usb-drive
Turn it off after you start your collection to prevent accidental reconnect attempts in flight that can cause errors. See https://learn.rockrobotic.com/lidar-powered-off-mid-flight
There are a few errors in PCMaster that indicate a calibration error in your collection. For a walkthrough on each see: PCMaster Errors Walkthrough
Did your LiDAR's battery die? Did a battery hot swap and lose power to the unit? Does your aircraft provide a constant reliable power source?
Are you sure that you are not only stopping your collection, but also shutting down the LiDAR properly (using the shutdown button in the GUI)? If not then you won't be populating the ppk.pcmp and ppk.pcpp files with your specific unit's parameters and you'll have to enter them in manually.
Generally there are two ways to fix these problems:
Option 1: Re-fly the mission.
Option 2: Contact firstname.lastname@example.org and we may be able to process your data manually. (This option does require a fee)