If you ever receive the following error while doing development in Visual Studio, don't fret, it just means your system is running low on memory. Close a few apps, or restart Visual Studio and/or your system, if need be, and then try rebuilding your app and it should work like a charm!
The build stopped unexpectedly because of an internal failure.
Microsoft.Build.Exceptions.BuildAbortedException: Build was canceled. Failed to successfully launch or connect to a child MSBuild.exe process. Verify that the MSBuild.exe "C:\Windows\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe" launches successfully, and that it is loading the same microsoft.build.dll that the launching process loaded. If the location seems incorrect, try specifying the correct location in the BuildParameters object, or with the MSBUILD_EXE_PATH environment variable.