How to create new Dialog box or reset the default?

I deleted the about dialog box.
how do i create a new one?
when i click to reset button, i get the error: “Resource NEWSYSPAGES not found”.

A workaround: open the EXOP project file with a Zip archive like 7-Zip. And copy the dialog box files from an existing EXOP with the about box to the corrupted EXOP.