WinMerge version 18.104.22.168. WinMerge does a poor job of keeping two code files in snych. I have an example where a code file was greatly edited by a fellow developer. Many lines were removed. I tried performing a diff using WinMerge and it did poorly as compared to Microsoft VS WinDiff. In my example see that most method blocks starting at "private void CreateSurvivalGraph" do not synch up, even though they appear in both the "before" and "after" versions of the file. Microsoft's WinDiff kept all matching method synchronized all the way to the end of the files. WinMerge found hundreds of diffs that do not exist because it got "out of synch" somewhere. Maybe the files are just too big for WinMerge.