vCenter unable to add host.

[malabelle]

***** Resolved... esxi 5.5 u3 is not compatible with vCenter 5.5 u2. should have checked the HCL. *****

Hi.

I have a vcenter with auto deploy. Version 5.5.

It is running fine with my "old" host.

I just plugged my new blade enclosure. The blade picks up the new image, boots, it pings. But when com.vmware.rbd tries to add it to the vcenter it fails with the error:

Add standalone host Cannot contact the specified host (esx.blabla). The host may not be available on the network, a network configurati-on problem may exist, or the manageme-nt services on this host may not be responding. com.vmware.rbd

I tried switching the host profile. same thing.

The host still ping, it answers on the 443 port, I can connect to it from my vsphere client.It is also on the same network as all my other esx hosts, so vCenter can ping and access this host.

Any ideas?