Cloudscraper ends up with error that looks alike:
Command '"C:\Program Files (x86)\Migrate2iaas\Cloudscraper\Migrate\Migrate\Windows\vss\vshadow\bin\x86_64\6.1\vshadow.exe" -p \\.\c:' returned non-zero exit status 2
Cloudscraper relies on Microsoft Volume Shadow Snapshot service.
Sometimes the service rejects to perform snapshot. It may happen due to variety of reasons.
Run "cmd" and type:
vssadmin list providers
vssadmin list writers
1. Non-system snapshot provider blocks the snapshot.
2. One of snaphsot writers blocks the snapshot.
1. In case "vssadmin list providers" output lists Acronis VSS Provider (but you have no Acronis software installed) you should remove it manually, see https://forum.acronis.com/forum/27806
2. Stop all services (like ISS, MSSQL) related to the listed writers. Restart the migration.