Thank you for writing in, 2 issues I saw here, first your version of Modern Events Calendar is outdated and second you rename the updated Pro folder to something than
To resolve this please navigate to Plugins panel and deactivate the Modern Events Calendar you need to update this later.
Then connect to your server via FTP or cPanel's File Manager, navigate to /wp-content/themes/ Identify which of your two Pro folder is the updated one, you can check that by opening the
style.css file on those folders and you'll see the version in there.
Rename the updated version of Pro folder to just
pro then navigate back to your admin dashboard and reactivate the updated Pro theme, you can then delete the old one to avoid confusion. Then validate your PRO.
Then update your Modern Events Calendar and reactivate it.
Remember to clear all your caching features (plugin, server-side, CDN, and browser's cache) after updating so that the code from the latest release is always in use. This will help you to avoid any potential errors.
Hope it helps,