--- a/SequenceableCollection.st	Thu Sep 21 11:13:48 2017 +0200
+++ b/SequenceableCollection.st	Thu Sep 21 15:27:23 2017 +0200
@@ -1,3 +1,5 @@
+"{ Encoding: utf8 }"
+
 "
  COPYRIGHT (c) 1989 by Claus Gittinger
 	      All Rights Reserved
@@ -10213,6 +10215,9 @@
         lineString := self at:lineIndex.
 
         lineString notNil ifTrue:[
+            lineString isString ifFalse:[
+                ConversionError raiseWith:lineString errorString:' - string required in collection'.
+            ].
             withEmphasis ifTrue:[
                 lineString hasChangeOfEmphasis ifTrue:[
                     needEmphasis := true
@@ -10416,8 +10421,8 @@
 
     "
 
-    "Created: / 17.6.1998 / 12:30:32 / cg"
-    "Modified: / 17.6.1998 / 12:31:59 / cg"
+    "Created: / 17-06-1998 / 12:30:32 / cg"
+    "Modified: / 21-09-2017 / 12:46:43 / stefan"
 !
 
 joinWithAll:separatingCollection