Updated: 01/05/2023
For those of us that have no choice but to use the older BBC iPlayer add-on, like in my case support for the Matricom MX2 box has been dropped post Kodi Leia. I have quick patched version 3.0.52 iPlayerWWW add-on to enable video listings again (I'm not sure if the audio side is broken I don't use it).
I doubt this is any use to any of the main Kodi users as they'll all have cutting edge devices (and I CBA to sign up to their forum), which is why I've posted here and I'd thought I'd share.
I am not affiliated with the official add-on maintainers and this does not bring all the new features which come with version 4.x. Also all credit goes to the maintainers for the fixes in the functions borrowed.
This is simply a copy/replace of the functions ParseSingleJSON and ParseJSON in resources/lib/ipwww_video.py, in version 4 to 3.0.52, which appears to have gotten things rolling again.
In Kodi; install from zip in the add-ons section. If you see no change you may need to uninstall the old add-on and install this one (note: uninstalling may remove your Kodi iPlayer favourites, so be mindful).
Enjoy 
qUE