K2 requires Microsoft MSBuild Tools installed on the K2 Server for K2 Package and Deployment to function correctly.
Prior to .NET Framework 4.0, MSBuild was bundled as part of the Framework installation. Starting with .NET 4.0 it is bundled with Visual Studio (2010 and greater). For K2, if any K2 supported version of Visual Studio is present on the K2 Server machine, these tools are available.
Deploying a workflow with K2 Package and Deployment in K2 4.6.11 without the MSBuild Tools installed results in errors similar to the following: