HelloTheBobkin and Thanks!
Right on the spot, vcenter was update 1 and the hosts update 3
Vcenter appliance version 6.7.0.21000 6.7.0.11727113
VMware ESXi, 6.7.0.14320388
Using VAMI, I take Vcenter to last Version and finally, could complete the assistant without inconvenience
Actual vcenter Version 6.7.0.40000 6.7.0.14367737
Thank you very much for pointing me in the right direction !