That solved it. I guess the archive was corrupted. I downloaded it again and it worked.

So I managed to actually run Clymore.
Now, the next problem is that some of the cards won't accept any straps. I have a rig with 12 RX580 cards. 8 of the cards work with - strap 1 applied to them with 30+mh, but the other 4 won't accept any strap from 1 to 4 and work with 24mh. I tried even with - POL4H1 to 4, but it's the same. As soon as Claymore starts applying straps to theese cards the rig restarts.