title: Why MSBUILD gets error from Rad Studio 10.3 IDE but from command line works?
body: <p>In a Rad Studio Rio C++ project, when I compile, I get:</p>
  
  <pre><code>MSBUILD : error E1028: unable to open output file '.\Win32\Debug\Unit1\obj': 'no such file or directory'
  </code></pre>
  
  <p>Note that it shows <code>Unit1\obj</code>, not <code>Unit1.obj</code>.</p>
  
  <p>It works fine if I compile from command line using MSBUILD <code>MyProject.cbproj</code></p>
  
  <p>Also, it works fine if I set on the <code>Run C++ compiler in separate process</code></p>
  
  <p>Also, I have found that the problem is only when I use the Configuration Manager, assigning to the projectt an <code>.optset</code> file.  If I unlink this .optset file, then it compiles from the IDE again.</p>
  
  <p>It seems a bug.</p>