Problem with PHP 8.0

Hi,

I tried to set PHP 8.0 for mondeoz.com but the website isn’t working, I have a blank page.
I switched back to 7.4 but I need to make this change for obvious security reasons.
Can you help?

Thanks

Fyi I’m using Newspaper 12.3

Hi, problem solved. Now I have an alert related to the theme:
Warning: A non-numeric value encountered in /mondeoz.com/wp-includes/functions.php on line 493

Hi, no I did not modify this file and I have no idea why it’s installed there instead of wp-content
I created this website in 2017 and used the standard template at that time.

Lines 486 to 498 are:
if ( 0 === $bytes ) {
/* translators: Unit symbol for byte. */
return number_format_i18n( 0, $decimals ) . ‘ ‘ . _x( ‘B’, ‘unit symbol’ );
}

foreach ( $quant as $unit => $mag ) {
if ( (float) $bytes >= $mag ) {
return number_format_i18n( $bytes / $mag, $decimals ) . ‘ ‘ . $unit;
}
}

return false;
}

Moreover, when I look through the FTP, I see another file in:
/mondeoz.com/wp-content/themes/Newspaper/functions.php

Sounds like a mission…

Moreover, I don’t understand. Could you kindly explain why and how?
This plugin helps to downgrade a WP version, how could I “reinstall” with it? Wouldn’t it be easier to click “Re-install version 6.1.1-fr_FR” in Dashboard > Updates? But what would be the benefit? And wouldn’t I risk to loose all my settings?
Thanks

Still have the same problem.
Can you help?