Autodesk Developer Network 2011
Autodesk
Migration
§Revit uses .NET Framework 4.0 (VSTA .NET 3.5)
§Visual Studio
§VS 2008 (no debugging) or
§VS 2010 with framework target of .NET 3.5 or 4.0
§Add-manifest
§No more .ini file
§<VendorId>ADSK</VendorId> (must)
§<VendorDescription>Autodesk, www.autodesk.com</VendorDescription>
(optional)
§RDS: Registered Developer Symbol www.autodesk.com/symbreg
§
§Re-reference managed modules
§RevitAPI.dll
§RevitAPIUI.dll
§
§
§
Revit 2012 API has now been enhanced to run with MS .NET 4.0 runtime

Use Visual Studio 2010 with framework target of .NET 3.5 or 4.0
The existing Addins compiled with VS 2008 will continue to work but will run outside debug environment

With changes to the manifest file in Revit 2012, the INI file can no longer be user to load an add-in.
It is now mandatory to provide a Vendor Id in the manifest file. The Vendor id is a mandatory string which conforms to the Autodesk’s Registered Developer Symbol (Or the RDS) standard. This Vendor Id should be a 4-character “prefix” registered with Autodesk as per Autodesk’s vendor Id Standard.
The VendorDescription is an optional string which contains the vendor’s legal name and other pertinent information.  This vendor description might show up in pop-ups error messages saying whom to contact in case of errors.

In your existing plug-ins, you will have to re-reference the two Revit API dlls to make them run in Revit 2012 using its API.