title: Visual Studio - Can't reference tlb / dll anymore
body: <p>I'm writing a C# application that communicates by a COM-Interface with another program. So far ervything worked well.</p>
  
  <p>After I deleted the .tlb in the vs reference dialog and unregsitered it by reglibv12.exe I was not able to add it anymore.</p>
  
  <p>The error says:</p>
  
  <blockquote>
    <p>Reference to <em>tlb path</em> could not be added. Please make sure the file
    is accessible and that is it a valid assembly or COM component.</p>
  </blockquote>
  
  <p>This problem occurs not at a collegues pc who uses also vs with default settings.</p>
  
  <p>What I tried so far:
  - Reinstalling Vs
  - Delete the Vs user folder
  - Register the tlb again with reglibv12.exe
  - Run Vs as admin
  - Put the tlb in the Vs project folder
  - List the assemblys with Gacutil.exe \l -> Where my tlb was not listed</p>