diff -r 6cf16e5bfbf9 -r c52d1460cea8 editors/Viewer.py
--- a/editors/Viewer.py	Sat Aug 19 17:17:54 2017 +0300
+++ b/editors/Viewer.py	Sat Aug 19 18:12:20 2017 +0300
@@ -268,7 +268,7 @@
         message = None
         try:
             values = eval(data)
-        except:
+        except Exception:
             message = _("Invalid value \"%s\" for viewer block") % data
             values = None
         if not isinstance(values, TupleType):