Results 2 comments of victor

@dreddy-work , I add the following section to the app.config of .net v4.7.2 framework project, no issue appears. ``` ``` It seems that the issue locates in "RichEdit v4.1".

@RussKie , I'm not an expert to do that. The easiest way for me is to set the RichTextBox's font to "Calibri".