This message should be self-explanatory. It's an ahead warning meant to give you adequate time to prepare to upgrade your PHP version since your current one is going to become end of life next year. The message tells you that PHP 7.3 has entered Security Maintenance on December 6th, 2020 and will become end of life on December 6th, 2021. These dates are not arbitrary. They come from the official PHP site: https://www.php.net/supported-versions Please read that page, it explains the difference between PHP versions which are actively supported, in security maintenance and end of life.
In any case, the message is an ahead warning to update to PHP 7.4 before December 6th, 2021. This means that you need to go through your site's extensions and see which ones are compatible with PHP 7.4 and upgrade to it.
Do remember that PHP 7.4 has been released a year ago, in December 2019. In other words you already had a year to update to it, but you haven't. This is why you cannot hide this message and why this message is displayed at the top of the page of our software, not at the bottom or somewhere you wouldn't see it and it wouldn't bother you.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!
