The issue occurs if the port groups names are not the same across all of the ESX hosts in the network. This prevents VM migrations. An error like “Currently connected network interface‘device’ uses network ‘network’, which is not accessible” can appear in vCenter. This error block definitively a VM migration
To work around the issue, ensure that the virtual machine network port groups names are the same across all of the ESX hosts that participate in the vMotion operation, as explained in the following vmware knowledge base article.
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