You may know the issue when opening a BizTalk orchestration and it opens like this:
Note: I blurred the code to protect the name of my client.
Not much you can do about it, except right-clicking the orchestration and clicking ‘Open With…’ and choosing the BizTalk Orchestration Designer.
However, if you close the BizTalk Orchestration Designer again, and double-click the odx file, it once again opens in the first, yet useless, view.
An easy fix
The culprit is actually not in the orchestration, but can be found in the BizTalk project (.btproj) file:
Open the Visual Studio BizTalk project (.btproj file) containing the orchestration with your favorite editor and search for ‘Designer’:
You’ll notice that the orchestration, which refuses to open in the Orchestration Designer, actually has a node SubType which is set to “Designer“.
Now remove the line containing this node from the file in your editor, save the file and reload the file in Visual Studio.
If you now double-click the orchestration, it now opens in the BizTalk Orchestration Designer again!
Don’t forget to check-in/commit your changes 😉
Hope this helps! Cheers!