diff -r 0a8e30a7b10e -r b99283eed13c src/Pure/Tools/print_operation.scala
--- a/src/Pure/Tools/print_operation.scala	Sat Apr 01 19:16:19 2017 +0200
+++ b/src/Pure/Tools/print_operation.scala	Sat Apr 01 19:17:15 2017 +0200
@@ -32,7 +32,7 @@
       val ops =
       {
         import XML.Decode._
-        list(pair(string, string))(YXML.parse_body(msg.text))
+        list(pair(string, string))(Symbol.decode_yxml(msg.text))
       }
       print_operations.change(_ => ops)
       true