Once a ndi file fails to import via the inventory import task, it will be removed to the one of the sub folders of %ProgramData%Flexera Software\Incoming\Inventories\Badlogs\

• failure: Any generic failure resolving the ndi file
• invalidcompression: applies to zipped files where the checksum of the file doesn't match (this is to ensure security)
• invaliddata: ndi files are incomplete or corrupt
• invalidformat: ndi files had incomplete xml
• invalidlicense: no blade available for customer. e.g. vmware server inventory without vmware blade the file gets rejected and put into location.
• invalidtenant: not able to find the tenant context. It's only valid for On-Demand or MSP configuration

If you need more detailed information, you can try re-importing the inventory file with the below steps to see what error happens.
1. Move the inventory file back to %ProgramData%Flexera Software\Incoming\Inventories\
2. Navigate to C:\Program Files (x86)\ManageSoft\DotNET\bin
3. Run the command: mgsimport.exe -e -l -o create_no_windows=True -- -t inventories
4. The detailed error messages will be displayed on the console