Error in a VS 2012 project

ShaningYu

I installed VS 2012 Ultimate and also ArcObjects WDK for MS .Net FW.  Then I opened a .sln on the VS 2012 but got the Error below:

The "ValidateAddInXMLTask" task could not be loaded from the assembly ESRI.ArcGIS.AddIns.SDK, Version=10.2.0.0, Culture=neutral, PublicKeyToken=8fc3cc631e44ad86. Could not load file or assembly 'Microsoft.VisualStudio.Shell.9.0, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The system cannot find the file specified. Confirm that the <UsingTask> declaration is correct, that the assembly and all its dependencies are available, and that the task contains a public class that implements Microsoft.Build.Framework.ITask.

I checked the Registry Editor, and did see the item: ESRI.ArcGIS.AddIns.SDK.11, Version="10.2.0.0"

What should I do to debug it?  Appreciate if you can help for this issue.

JaredCaccamo

Shaning Yu‌ It would be helpful to know more of the system/environment information( which version of ArcObjects and your type of project ) but give this a shot since it tends to be a common issue that is a result of that error.

1- Unload the project (in Solution Explorer) by right-clicking the Project and selecting "Unload Project"
2- Right click the unloaded project and select "Edit Project". An XML file opens (*.csproj).
3- In the XML, search for the attribute value that contains the following string: ESRI.ArcGIS.AddIns.targets. You will find three occurrences of this string.
4- Change this string to the following: ESRI.ArcGIS.AddIns.11.targets. Essentially, add the integer "11" after Addins.
5- Save the XML (*.csproj) file, and close it.
6- Right-click the project, and select "Reload Project".
7- Recompile your project. The error should have been resolved.
8- Repeat the above steps for all Add-In projects in your solution.

Similar reference for How to Port your Addin from a previous version but a little different since it is intended for 10.3 and lower to 10.4 but makes similar adjustments.

Best of luck