diff --git a/Duplicati/Library/Main/Operation/FilelistProcessor.cs b/Duplicati/Library/Main/Operation/FilelistProcessor.cs
index 28d599879..d0ff235b8 100644
--- a/Duplicati/Library/Main/Operation/FilelistProcessor.cs
+++ b/Duplicati/Library/Main/Operation/FilelistProcessor.cs
@@ -112,7 +112,7 @@ namespace Duplicati.Library.Main.Operation
 
             if (doubles.Count > 0)
             {
-                var s = string.Format("Found remote files reported as duplicates, either the backend module is broken or you need to manually remove the extra copies.\nThe following files were found multiple times: ", string.Join(", ", doubles.Keys));
+                var s = string.Format("Found remote files reported as duplicates, either the backend module is broken or you need to manually remove the extra copies.\nThe following files were found multiple times: {0}", string.Join(", ", doubles.Keys));
                 log.AddError(s, null);
                 throw new Exception(s);
             }