Lately in support we have been getting lots of questions that tie back to configuration usage. This can manifest itself in many different ways:
There are more, but you can see a pattern here. The root cause tends to be the configuration being used across the different environments. Recommendations really start with stating that the configuration file or registry based configuration be examined to make sure it is pointing to the correct AOS/database combination, and the WCF configuration information is correct. More information on this can be found at http://technet.microsoft.com/en-us/library/aa569651.aspx .
Once this has been verified, make sure to examine what configuration is being used to open Visual Studio 2010. This process is discussed at http://msdn.microsoft.com/en-us/library/gg889291.aspx .
So, in summary, if you are seeing strange behavior where objects are not being found, deployments go to the wrong stop, or things like the Visual Studio 2012 Application Explorer doesn't seem to match what is being displayed in the Dynamics AX 2012 Development workspace, you may want to start looking at your configurations and which is being used in Visual Studio 2010.