--- a/Tools__NewSystemBrowser.st	Sun Dec 15 14:52:22 2019 +0100
+++ b/Tools__NewSystemBrowser.st	Mon Dec 16 11:39:51 2019 +0100
@@ -36640,6 +36640,7 @@
         classes size == 1 ifTrue:[
             "/ fetch from the single class, sorted by underlying version
             knownTags := classes first sourceCodeManager knownTagsFor:classes first.
+            knownTags := knownTags asNewOrderedCollection.
         ] ifFalse:[
             "/ fetch from all classes
             knownTags := self allKnownTagsInClasses:classes.