I had just extended my web application to allow for SSL access. In order to do some configuration, I needed to go into Central Administration->Manage Service Applications. I was unable to manage some applications because Central Administration was throwing the following exception:
System.IO.FileLoadException: The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
Not much more available in ULS.
It looks like just a simple iisreset did the trick. It probably has to do with the fact my demo server has Central Administration on the same server as the Service Application (just like the issue with the User Profile Application being on the same machine as Central Administration).