My experience is you will get this error if you try to import the standard Gen10 spp's when in fact you need to add something like VMware ESXi 7.0 Upgrade Pack
to the amp pack server, then when you return to vCenter settings and then add that pack, it will succeed.
Any luck? I've opened a ticket with HPE for the same issue. I first tried the latest PSP but that failed when clicking the 'link' funciton. I then tried the SPP-VUP version and it also failed. HP didn't seem to have any ideas.
same problem on my site - one week ago, I opened a HPe ticket but still no solution.