There's not really an uninstaller for max. Uninstalling would basically mean trashing the max5 folder. Unless you have moved around stuff in this folder, there would not be a reason that objects would not be found. Unless maybe the prefs got corrupted somehow, which you then would have to trash... It would be nice if there would be an export of these settings (defaults and paths) but it is not too difficult to point out the files in the preferences folder that deal with these two.