title: C# revert to previous version
body: <p>My developer did not save the stable version of C# application( lets say v12) that we are developing. Now after bunch of enhancements we are at V20,  but the application has become crap at v20. So I asked the developer to revert back to v12, but the developer says he cant as he did not save that version. Fortunately he made a .dll file of v12 to test. So I asked him to de-compile v12 dll and revert the  code by looking at decompiled code as reference.Despite couple of attempts he was not able to restore and recreate stable v12.</p>
  
  <p>Can someone please advise if there is a way in C# to revert to previous version ?</p>
  
  <p>My application is total mess and the developer just cant fix it . I am really frustrated and concerned that months of development work could go to waste</p>
  
  <p>I am not sure if he is taking me for a ride or genuinely there is no way to revert to previous version.</p>
  
  <p>ps: I do not have any coding background.</p>
  
  <p>Thank you in advance.</p>