I have found that there is a limit to how long a hyperlink can be... if it is too long, WPTools4 dies with an access violation when saving, such as saving to a file. For example, I use the hyperlink attribute to duplicate the hyperlink marked text elsewhere in a document on a mail merge. (This is accomplished using bookmarks in WPTools5, but this is out old legacy app which uses WPTools4 and I can't change this).
Anyway, if the user selects a long paragraph, which might be 1000 chars or more, and clicks the Hyperlink toolbar button. It marks if fine, but I then get an access violation if I try to use this hyperlinked text in a mailmerge, or simply attempt to "SaveToFile".
WPTools 4.25
Delphi 5