Problems with Clickable Links, Buttons and Boxes in Captivate Version 9.0.0.223

Before concluding that the Open URL actions are not working, check whether or not they may actually be opening in another browser window or tab that does not currently have focus. The linked content might actually just be sitting underneath the currently visible window.

I had this happen a year or so ago with one client's LMS.  I was reviewing another company's elearning modules where several PDFs were supposed to be opened and read by the user.  On clicking the links to open these PDFs, nothing seemed to happen.  So, I logged the issue as a bug with their development team, only to find that the PDFs had actually opened in browser windows UNDERNEATH the content pages where the URL links appeared.

Maybe something similar is happening to you.

I have experienced something similar when developing a project for tablet and mobile devices...  

Sometimes, the browser may incorrectly render the project which causes some links, especially those that use text to be incorrectly positioned.

Is it a specific kind of link, i.e. one opened using a clickbox, or a button or is it just a hyperlnk that is the issue?

For me it was text based hyperlinks - I replaced these with a clickbox that would open the link when clicked, so the user would still experience the same functionality when "clicking" the hyperlink.   

That is an old version, and none of the available updates were installed. That may be the origin of your problems with linking to an URL. Try at least to update the version even if you keep to CP9. You also need to know that this version may not be compatible with your present OS version.