Build fails after upgrading Visual Studio 2010 project to Visual Studio 2013

I have a SharePoint 2010 solution created with Visual Studio 2010, works fine. Our new development VM's will not have Visual Studio 2010 installed, only Visual Studio 2013. The project will still be a SharePoint 2010 solution. When opening the solution in VS13, VS upgrades the solution and everything looks OK. However, the build fails with the following in the output window:

C:\Program Files (x86)\MSBuild\Microsoft\VisualStudio\v12.0\SharePointTools\Microsoft.VisualStudio.SharePoint.targets(489,5): error MSB4044: The "TransformFiles" task was not given a value for the required parameter "IsDebugging".

Double clicking the line in the output file opens the target file to the following section:

<TransformFiles IntermediatePath="$(PackageIntermediatePath)"
                    ProjectId="$(ProjectGuid)"
                    ProjectService="$(ProjectService)"
                    IsDebugging="$(IsDebugging)"
                    TranslatedWorkflowsDestinationFolder="$(TranslatedWorkflowsDestinationFolder)"
                    AppManifest="@(AppManifestFile)"
                    PublishedFrom="$(PublishedFrom)"><Output ItemName="EnumeratedFiles" TaskParameter="EnumeratedFiles" /></TransformFiles>

I've created new projects and tried finding the differences, however cannot get the build to work. Any help would be greatly appreciated. Thanks!