I came across and issue today after doing a clean install of Windows and reinstalling AppFabric where the Microsoft.ApplicationServer.Caching.Client.dll was missing from the installed files. The dll is used to interact with the distributed AppFabric Cache in .net so it was important I got it working.
There are a number of posts across the internet complaining of the missing file but none provided an answer that solved my problem. I don't know what the root cause was (it may have been something like I only installed the caching components) but I could not find a solution.
It turns out, even though the file is not installed, the file does exist in the exe (I was using AppFabric1.1-RTM-KB2671763-x64-ENU.exe). So, using Universal Extractor, I extracted the files and just copied the Microsoft.ApplicationServer.Caching.Client.dll (the version found in the installer is 1.0.4632.0) to the AppFabric directory in:
C:\Program Files\AppFabric 1.1 for Windows Server
I could then happily reference the file in Visual Studio and all is well with my project.