Thank you for looking at my question. I have upgraded to 10.4, re-built my applications in VS2013. At which time I was not getting the esriAddIns created. With help from a prior question I did the following:
I went to my Program Files (x86)\MSBuild\Esri and the AddIns.target file is ESRI.ArcGIS.AddIns.target. In the VBPROJ file (from 10.3) it was ESRI.ArcGIS.AddIns.11.target. I removed the .11 from the three references and made sure
the CSPROJ file was updating which it was.
I also found that the AddInTargetVersion was set to
10.3. I changed it to 10.4
Once I made the changes the esriAddIn file was created for each of my applications.
Now when I go to run the addins I get the following error messages.
“Application.OnStartup - event invocation for COM objects requires event to be attributed with DispIDAttribute”
“Object or Application that generated Error: System.Core.”
I am working on trying to understand these messages, but if anyone can shed some light on these or point me in the right direction I would appreciate it.