title: Visual Studio Platform 2015 Toolset ='v141' cannot be found
body: <p>I'm trying to compile a project using OpenFrameworks (a library which uses C++) in Visual Studio. The build is set to Release and X64 and in the project properties I have set the Platform Toolset to Visual Studio 2015 (v140)</p>
  
  <p>However every time I try to build the project I get the same error (amongst others)</p>
  
  <blockquote>
    <p>Error MSB8020 The build tools for v141 (Platform Toolset = 'v141')
    cannot be found. To build using the v141 build tools, please install
    v141 build tools.</p>
  </blockquote>
  
  <p>I know v141 is from the new version of MSVS 2017 but I do not want to upgrade to as the new version is not compatible with OpenFrameworks. I have tried rebuilding the project from scratch several times and have also looked into the VCXPROJ file and verified that everything is set to V140 - and it is. All very bizarre. </p>
  
  <p>It seems that on build, something is setting a requirement for v141 but I cannot seem to find where this is coming from. Does anyone have an idea? </p>