Index: applications/editors/josm/plugins/graphview/src/org/openstreetmap/josm/plugins/graphview/plugin/preferences/VehiclePropertyStringParser.java
===================================================================
--- applications/editors/josm/plugins/graphview/src/org/openstreetmap/josm/plugins/graphview/plugin/preferences/VehiclePropertyStringParser.java	(revision 26220)
+++ applications/editors/josm/plugins/graphview/src/org/openstreetmap/josm/plugins/graphview/plugin/preferences/VehiclePropertyStringParser.java	(revision 26221)
@@ -45,5 +45,5 @@
         tr("Tracktype grades must be given as integers between 0 and 5.");
     public static final String ERROR_SURFACE =
-        tr("Surface values must not contain any of the following characters: ',' '{' '}' '=' '|");
+        tr("Surface values must not contain any of the following characters: '','', ''{'',  ''}'', ''='', ''|''");
 
     private static final List<Character> FORBIDDEN_SURFACE_CHARS =