ProblemThis applies to a scenario where AutoCAD is used as a managed application and file types have been configured for AutoCAD drawings (DWG files). A new instance of AutoCAD is started when an instance of AutoCAD is already running and a user opens a DWG file from Windows Explorer. This also applies when AutoCAD is started as an RES VDX extended application.
The default behavior of AutoCAD is to open a drawing in the already running instance.
CauseAutoCAD uses a different executable for the file type association.
For the Start Menu or the desktop shortcuts the executable acad.exe is used to start AutoCAD. For the file type association the executable AcLauncher.exe is used, which can be found in "C:\Program Files\Common Files\Autodesk Shared\AcShellEx".
SolutionUse the executable AcLauncher.exe for the file type association.
Create a new managed application that uses C:\Program Files\Common Files\Autodesk Shared\AcShellEx\AcLauncher.exe and create the following file type association.
File type extension: dwg
Command line parameters: /O "%1"
For the best user experience use the application option "Hide application" to prevent the application from appearing in the Start Menu, Quick Launch or Desktop.