There seems to be something about testvm1 that it's not liking. Can you do a 'get-vm testvm1 | format-list *' and post?
Clone operation is only supported by vCenter Server, so you can't perform clone vm when connected directly to Esx(i).
exactly, you are right! my clone operation via ESXi direclty.
when I changed ESXi to vCenter for the connection server, my clone operation performed successfully.
thank you for posting. my problem was solved by Yasen's comment. I had simple mistake way of clone operation.