Datacenter Wizard. Error -2145833073 while importing the datacenters

Hello,

I've installed vWorkspace 7.5 and I'm getting an error importing datacenters from the vCenter Server (release 4.1)

I've checked the user firewall and user credentials and all is ok but the datacenter wizard lauchs a security error -2145833073.

"An error occurred while importing the datacenters from virtual management server https://vcenterServerdnsName/sdk. 

Currently I'm also using this Vcenter Server with vWorkspace 7.2 MR1 without problems. Can I do this?

In the vWorkspace 7.5 Administration Guide doesn't  talk about a keystore nevertheless I have created a vmware.keystore.

I've applied the SOL52378, but this doesn't solve my problem. (I know that this SOL52378 is only for vWorkspace~5.8 - 6.0,

but it solved same problem in my vWorkspace 7.2 MR1 setup few months ago).

Suggestions?

Thanks.