Issue:
The following LDAP error may occur when you try to do an Active Directory search in K2.Net Service Manager or K2.Net Studio after you added multi domain support to K2Server.config:

An exception has occurred while trying to connect to the following data source:
Data Source Path="LDAP://DC=k2workflow,DC=com"
Data Source Type: Active Directory

Message:
The specified domain either does not exist or could not be contacted.

Solution:
Add the Domain Controller name to the LDAP string:
<DataSource Path="LDAP://DomainControler/dc=DomainName,dc=com" NetBiosName="MyNetBiosName" Type="ActiveDirectory" />