Hey @Mariano,
Sorry to hear about some issues with the featured images. In the last update, there were no changes, but I am referring to a one-version jump. For example, version 4.1.2 to 4.2.2.
1. What version of the plugin was your client upgrading from?
2. Can you post the system information of that site to this thread? Here is how → https://theeventscalendar.com/knowledgebase/sharing-sys-info/
3. Can you explain what the actual newfound issues with featured images are? Are they just not showing up? Please share a link to a page on your site where this can be seen, if possible…
Thank you!
Cheers,
George