У вашего броузера проблема в совместимости с HTML5
How to Increase PHP memory Size in WordPress is explained https://youtu.be/Y2gXtGsn220 for WordPress memory size increase using php.ini and also wp-config.php define PHP constants
you can place this
define( 'WP_MEMORY_LIMIT', '96M' );
define( 'WP_MAX_MEMORY_LIMIT', '256M' );
in wp-config.php file
Or you can use cPanel php.ini server file configuration to add
memory_limit = 512M
This will ensure that PHP memory size used by WordPress now has enough limit.
Note: your server may not allow increase of memory size PHP uses, check with your web hosting company if this is the case.
For more WordPress related video tutorials visit:
https://www.youtube.com/playlist?list=PLvY3VKvXDMyplHQsZ4ZoeSImK-alQlF3m
Thank you for learning with me