Based on your question, it could be a number of things so I'll run through the list I always go through when doing this. If this doesn't help, provide a little more background and I might be able to give you a more useful answer.
Luckily UCMA 4.0 installs a whole lot easier than the previous versions did. UCMA 4.0 applications must (must, must) be compiled 64-bit to run in production. The SDK will allow 32-bit compiles, but the SDK requires an installation of Visual Studio to install. Because of the problems your running into, I'm led to believe you might be installing the wrong "kind" of UCMA bits on the server.
Check that you're using UCMA 4.0 Runtime, not SDK
On the server, you want to install the UCMA 4.0 Runtime, not the SDK. That should get you your dependencies. In the references within your application, you want only the Microsoft.Rtc components that you're using. SIPEPS.DLL
and such are used by them but in the projects I've written against UCMA, it is not referenced directly in any one of them.
Check your pre-reqs
I have UCMA 4.0 up and running (perfectly, first time) on Windows Server 2008 R2. I noticed on the pre-req's it had a requirement for Service Pack 1 to be installed (my environment is up to the latest patch levels on everything).
You didn't specify your patch levels and since you indicate that you're not having problems on later versions, I suspect this might have something to do with it.
You'll also need:
- .Net Framework 4.5 (latest 4.5 -- I think 4.5.2 as of this moment). Make sure this is installed before even running the installer for UCMA.
- Server has to be 64-bit (all of Lync has this requirement)
- If you are able to get up and running but have difficulty doing basic things related to connecting, etc, check your AV software. I've encountered a situation where a Symantec Endpoint Protection interfered with UCMA despite having firewall rules in place that didn't appear to be a problem.