title: fatal error C1001: INTERNAL COMPILER ERROR (compiler file 'msc1.cpp', line 1794)
body: <p>I tried to compile a project with Visual Studio 6 SP6 and got the following:</p>
  
  <pre><code>usbcore.h(18) : fatal error C1001: INTERNAL COMPILER ERROR
      (compiler file 'msc1.cpp', line 1794)
       Please choose the Technical Support command on the Visual C++
       Help menu, or open the Technical Support help file for more information
  </code></pre>
  
  <p>Line 18 of usbcore.h contains the include directive:</p>
  
  <pre><code>18: #include "usbiface.h"
  </code></pre>
  
  <p>Empty or non-existing usbiface.h produces the same error. I commented this line and got the same error but for the next include file.</p>
  
  <p><strong>To sum this up:</strong> the compiler error occurs for each <code>#include</code> directive that refers to the common project headers.</p>