Ever since upgrading to Mountain Lion I have had endless problems with Apps and firefox. My current issue is that I am unable to download files using firefox ever since the update. I get a messagebox saying the error
/Users/username/Downloads could not be saved, because an unknown error
occurred.Try saving to a different location.
Best Answer
Once again, the problems are not with permissions. In Firefox's preferences, on the general tab, Set Firefox to "Always ask me where to save files" under Downloads. Files will download fine, to the Downloads folder or anywhere else.