While moving vApp (MoveVapp) between OVDCs error 'Specified parent network XXXX (com.vmware.vcloud.entity.network:...) is invalid. Either it is inaccessible in the VDC or it is not part of the correct organization'
vCloud Director 10.3
The network logical resource referenced is the vdc_logical_resource.id of the source Org VDC network that the vApp is using which is indeed not available to the destination Org VDC.
If vApps have to be moved or copied between OVDCs the networks have to be shared and OVDCs are backed by Provider VDC in the same vCenter server
To make the organization VDC network available to other organization VDCs within the same organization, toggle on the Shared option.