I stepped into a deep hole while developing SSIS packages for CRM using KingswaySoft's software. Packages stopped running in Visual Studio 2012.

As soon as the package was executed, it immediately switched to Cancel state, as reported by the Output window. Nothing was written to the Execution Results, no breakpoint triggered, no logs were written.

In my last ditch effort, I looked at the project's properties, and under Configuration Properties > Debugging I noticed the Run64BitRuntime was changed from its default value. I switched it to False, and my packages were running again.