Hello Ingrid and welcome to the forums!
How are you trying to copy the VM from one host to the other?
A supported and the recommended way to do this is via the ovftool command line tool.
You can find a detailed write-up e.g. here: https://www.virtuallyghetto.com/2012/06/how-to-copy-vms-directly-between-esxi.html
That looks like the source VM had one or more of its VMDK-files assigned via an absolute path.
I would suggest you check and if necessary adjust the paths in the vmx-file and then reregister the VM.