Don't try to loop over None. fix #2268

couchpotato/core/plugins/manage/main.py

@@ -222,6 +222,7 @@ class Manage(Plugin):
 
         groups = fireEvent('scanner.scan', folder = folder, files = files, single = True)
 
+        if groups:
             for group in groups.itervalues():
                 if group['library'] and group['library'].get('identifier'):
                     fireEvent('release.add', group = group)