After you have created the connection property instance you need to go to the virtualization tree in the property dictionary and assign that connection instance to your Vcenter server's "VIRTUAL_ENTITY_CONNECTION"
Yeah Mike is right, After that make sure you set VIRTUAL_ENTITY_TYPE as "VMware Virtual Center".
I already have VIRTUAL_ENTITY_TYPE set with the default instance created.
The problem is i am able to connect when i use default instance....but when i create custom instance and then assign it to VIRTUAL_ENTITY_TYPE it doesn't work.
This was the question??
Are there any differences between the two? For example, if you're leveraging a domain service account you don't put the domain info in CONNECTION_DOMAIN. You enter the account in as DOMAIN\username in the CONNECTION_USER field.