This question is locked. New answers and comments are not allowed.
It appears something has either changed with Fiddler or Symantec. I have several users who were on an older release of Fiddler and we also upgraded our endpoint protection from SEP 14 MP2 to RU1 MP1. Since then, Symantec will prevent the install of any new Fiddler install/upgrade. The old version of Fiddler still works (4.6.2.32002). Any ideas?