title: VisualStudio 2012 update 4 c# endless loop / debugger hang
body: <p>What are the reproducible known states, conditions, or requests that cause the VisualStudio Debugger to "spin endlessly" or hang?</p>
  
  <p>(Reworded because original question below was put on hold - Please consider decision to place question on hold because it IS reproducible and it is not quite as simple as a "typo" which the debugger would have caught and refused to set breakpoint like it does with other conditions it knows it is unable to handle.)
  Has anyone else observed VisualStudio "spinning endlessly" when trying to use the debugger with a conditional breakpoint?
  I waited more than 5 minutes with one cpu core "pegged" for "something to happen in my app."  During this time visualstudio was using >75% of one cpu core with about 2 or 3% reported as being used by the app.  Pausing appeared to have no effect.</p>
  
  <p>Strangely the app started running normally and brought up the login screen after I disabled the conditional breakpoint.  I was then able to re-enable the conditional breakpoint and continue using the debugger with the conditional breakpoint active.</p>