Workflow quirk: cannot access this inline location reference

Activity '{0}' cannot access this inline location reference because it is only valid for activity '{1}'. Only the activity which obtained the inline location reference is allowed to use it.

Inside my assign activity:

' foundfiles is IEnumerable(of String)
foundFiles.Where(Function(file As String) FileNameBlacklist.Any(Function(blacklistItem) System.IO.Path.GetFileName(file).StartsWith(blacklistItem)) = False)

Not sure if this or the subsequent access was failing, however changing it to this fixed it:

foundFiles.Where(Function(file As String) FileNameBlacklist.Any(Function(blacklistItem) System.IO.Path.GetFileName(file).StartsWith(blacklistItem)) = False).ToList().AsEnumerable