I have used this AllVideo plugin before in custom modules and this time it is not working. This site is on Joomla 3.9.3 and I am typing in the embed code - {youtube}4NWh8dKNXts{/youtube}. I recently downloaded the newest jw plugin 4.8. This plugin does work when I enmbed the code in an article, not not a module.

The site is: mitzidesign.info/MStest/

thanks!

Thanks so much! This solved the issue!

Dear Fotis, I hope you can help me out . I have slightly the same problem as Mitzi Gilbert, with that understanding that I am not using a Custom HTML Module but J51 Carousel Module.
Till the upgrade to Joomla 3.9.6. I had pasted the All Video code {youtube}..code..{/youtube} in a column and several video players appeared (per column).
However since I have upgraded to Joomla 3.9.7 (and 3.9.8) the videoplayer doesn't appear anymore in the frontend. One sees the All video code appear.
I don't have the tab Options in this J51 Carousel Module to enable Prepare Content.
Do you think it is still possible to combine this module with All Videos?
Or should I look for another Module which can make a slight show out of the video.
Thank you so much for your help. All best.

Thank you Fotis. I have the developers (joomla51) and they are trying to solve the problem.

Ciarán, the very helpful developer of Joomla51 professional templates first advised me to update the module but the result was that module did not appear at all anymore. So then he created an override for my module and enforced the prepare content option.