Your original message indicated that you could connect to one Kepware server and not another Kepware server. Are both Kepware servers remote from PCo? If so, you have to configure DCOM in order for PCo to have connected to any remote OPC Server.
We try to avoid DCOM where possible as it is always an effort to configure and maintain,
Are all PCo servers and Kepware Servers in the same domain? Are any Kepware servers located on other networks behind routers?
Regards, Steve