Hey,
Actually I got the last version 4.0.0 for a new project, but, I do not know why the banners do not show in Firefox (last version), They work good in CHrome and others web browser. What kind of issue can be?. Any idea?
Cheers!
Check your software section in your hosting, you will find a icon with the name "php configuration or php version", click there, and next select the last version you have listed.