title: Access denied error to .pdb files when building .netcore project in VS2017RC
body: <p><strong>Environment:</strong></p>
  
  <p>Microsoft Visual Studio Professional 2017 RC</p>
  
  <p>Version 15.0.26206.0 D15REL</p>
  
  <p>Microsoft .NET Framework</p>
  
  <p>Version 4.6.01586</p>
  
  <p><strong>Error:</strong> </p>
  
  <p>error CS2012: Cannot open [file.pdb] for writing -- 'Access to path [path to pdb file] is denied'.</p>
  
  <p><strong>Description:</strong></p>
  
  <p>I am building a .netcore application for .net core 1.1 with other libraries targeting .netstandard1.6. When I build the project I get above error. I cannot clean/build or run the project when it is in this state. Does not happen the first time the project is open, it seems very random, because it may work a few times before I get the error.</p>
  
  <p>When I navigate to it via explorer I also cannot delete the .pdb file nor the parent folder which is  either the netcore1.0 or netstandard1.6 folders in in the Debug directories. I cannot even change the permissions on the files or folders. I am an administrator on the pc.</p>
  
  <p>When I close Visual Studio and open it again all is fine and I can build again, which is not an answer.</p>
  
  <p><a href="https://social.msdn.microsoft.com/Forums/vstudio/en-US/ce514cbf-2c2f-4ae2-ace8-fbeaee115987/error-cs2012-cannot-open-filepdb-for-writing-access-to-path-path-to-pdb-file-is-denied?forum=msbuild" rel="noreferrer">Link to my question on the Visual Studio forum</a>.</p>
  
  <p>Thanks</p>