HTML Form Web Part. I can add the web part to a page, but when I try to open the source editor to insert some HTML, the editor will not open in a browser other than Internet Explorer. This is a pain because IE is not my default browser since many sites complain that IE is not a modern browser. Many of the users I support are not computer savvy and telling them to use IE, especially on a windows 10 PC, is difficult as IE does not come installed.