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https://blog.it-kb.ru/2013/12/07/hyper-v-the-virtual-machine-management-service-failed-to-authenticate-the-connection-for-a-virtual-machine-migration-at-the-source-host-the-specified-target-is-unknown-or-unreachable-0x80090303/
Hyper-V Live Migration - The specified target is unknown or unreachable (0x80090303)