format_paragraph_event wasn't returning 'break'
diff --git a/Lib/idlelib/FormatParagraph.py b/Lib/idlelib/FormatParagraph.py
index ed9f28d..f30898e 100644
--- a/Lib/idlelib/FormatParagraph.py
+++ b/Lib/idlelib/FormatParagraph.py
@@ -75,6 +75,7 @@
         else:
             text.mark_set("insert", last)
         text.see("insert")
+        return "break"
 
 def find_paragraph(text, mark):
     lineno, col = map(int, mark.split("."))