Migration of NSX VMs may display error:
Virtual ethernet card Network adapter 1 is not supported.
NSX VMs guestOS type is "otherLinux64"(as it is a custom OS that is the right type). And vmxnet3 is the network driver.
VMXNET 3 is supported only for virtual machines version 7 and later, with a limited set of guest operating systems:
Now that NSX VMs guestOS is "otherLinux64" and of none of the standard types, the vCenter Server thinks that the VNIC is not compatible with this VM and accordingly throws the warning.
This error is benign and can be safely ignored. Networking will work correctly after vMotion.