How to solve WordPress Webiste erros; Response is not a valid json response/ WP_Theme_JSON_Resolver::get_user_data()?

I am facing multiple errors on my wordpress website. I am not able to solve them, I have tried multiple solutions from across the web, but none have worked. Whenever I try to upload an image, I get the error that:

 The response is not a valid json reponse;

Also I face difficulty in updating present pages on my website and I also face issues in adding new plugins and themes. SSL plugin also gives error that:

Status code: 500, Server response: <script></script>{"fields":[{"default":false,"id":"ssl_enabled","visible":true,"disabled":false,"rec...

I tried debugging in wp-config file and get the foloowing erros on dashboard:

Notice: Function wp_enqueue_style was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. This notice was triggered by the low_diagnostic_glance_styles handle. Please see Debugging in WordPress for more information. (This message was added in version 3.3.0.) in /home/s3uoygwak2m1/public_html/wp-includes/functions.php on line 6085

Notice: Function is_feed was called incorrectly. Conditional query tags do not work before the query is run. Before then, they always return false. Please see Debugging in WordPress for more information. (This message was added in version 3.1.0.) in /home/s3uoygwak2m1/public_html/wp-includes/functions.php on line 6085

Notice: Function wp_enqueue_script was called incorrectly. Scripts and styles should not be registered or enqueued until the wp_enqueue_scripts, admin_enqueue_scripts, or login_enqueue_scripts hooks. This notice was triggered by the low_diagnostic_glance_custom_admin_script handle. Please see Debugging in WordPress for more information. (This message was added in version 3.3.0.) in /home/s3uoygwak2m1/public_html/wp-includes/functions.php on line 6085

Notice: WP_Theme_JSON_Resolver::get_user_data(): Error when decoding a theme.json schema for user data. Syntax error in /home/s3uoygwak2m1/public_html/wp-includes/functions.php on line 6085

Notice: WP_Theme_JSON_Resolver::get_user_data(): Error when decoding a theme.json schema for user data. Syntax error in /home/s3uoygwak2m1/public_html/wp-includes/functions.php on line 6085

Notice: WP_Theme_JSON_Resolver::get_user_data(): Error when decoding a theme.json schema for user data. Syntax error in /home/s3uoygwak2m1/public_html/wp-includes/functions.php on line 6085

Functions.php of theme:

<?php
/**
 * Astra functions and definitions
 *
 * @link https://developer.wordpress.org/themes/basics/theme-functions/
 *
 * @package Astra
 * @since 1.0.0
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit; // Exit if accessed directly.
}

/**
 * Define Constants
 */
define( 'ASTRA_THEME_VERSION', '4.7.3' );
define( 'ASTRA_THEME_SETTINGS', 'astra-settings' );
define( 'ASTRA_THEME_DIR', trailingslashit( get_template_directory() ) );
define( 'ASTRA_THEME_URI', trailingslashit( esc_url( get_template_directory_uri() ) ) );

/**
 * Minimum Version requirement of the Astra Pro addon.
 * This constant will be used to display the notice asking user to update the Astra addon to the version defined below.
 */
define( 'ASTRA_EXT_MIN_VER', '4.7.0' );

/**
 * Setup helper functions of Astra.
 */
require_once ASTRA_THEME_DIR . 'inc/core/class-astra-theme-options.php';
require_once ASTRA_THEME_DIR . 'inc/core/class-theme-strings.php';
require_once ASTRA_THEME_DIR . 'inc/core/common-functions.php';
require_once ASTRA_THEME_DIR . 'inc/core/class-astra-icons.php';

define( 'ASTRA_PRO_UPGRADE_URL', astra_get_pro_url( 'https://wpastra.com/pro/', 'dashboard', 'free-theme', 'upgrade-now' ) );
define( 'ASTRA_PRO_CUSTOMIZER_UPGRADE_URL', astra_get_pro_url( 'https://wpastra.com/pro/', 'customizer', 'free-theme', 'upgrade' ) );

/**
 * Update theme
 */
require_once ASTRA_THEME_DIR . 'inc/theme-update/astra-update-functions.php';
require_once ASTRA_THEME_DIR . 'inc/theme-update/class-astra-theme-background-updater.php';

/**
 * Fonts Files
 */
require_once ASTRA_THEME_DIR . 'inc/customizer/class-astra-font-families.php';
if ( is_admin() ) {
    require_once ASTRA_THEME_DIR . 'inc/customizer/class-astra-fonts-data.php';
}

require_once ASTRA_THEME_DIR . 'inc/lib/webfont/class-astra-webfont-loader.php';
require_once ASTRA_THEME_DIR . 'inc/lib/docs/class-astra-docs-loader.php';
require_once ASTRA_THEME_DIR . 'inc/customizer/class-astra-fonts.php';

require_once ASTRA_THEME_DIR . 'inc/dynamic-css/custom-menu-old-header.php';
require_once ASTRA_THEME_DIR . 'inc/dynamic-css/container-layouts.php';
require_once ASTRA_THEME_DIR . 'inc/dynamic-css/astra-icons.php';
require_once ASTRA_THEME_DIR . 'inc/core/class-astra-walker-page.php';
require_once ASTRA_THEME_DIR . 'inc/core/class-astra-enqueue-scripts.php';
require_once ASTRA_THEME_DIR . 'inc/core/class-gutenberg-editor-css.php';
require_once ASTRA_THEME_DIR . 'inc/core/class-astra-wp-editor-css.php';
require_once ASTRA_THEME_DIR . 'inc/dynamic-css/block-editor-compatibility.php';
require_once ASTRA_THEME_DIR . 'inc/dynamic-css/inline-on-mobile.php';
require_once ASTRA_THEME_DIR . 'inc/dynamic-css/content-background.php';
require_once ASTRA_THEME_DIR . 'inc/class-astra-dynamic-css.php';
require_once ASTRA_THEME_DIR . 'inc/class-astra-global-palette.php';

/**
 * Custom template tags for this theme.
 */
require_once ASTRA_THEME_DIR . 'inc/core/class-astra-attr.php';
require_once ASTRA_THEME_DIR . 'inc/template-tags.php';

require_once ASTRA_THEME_DIR . 'inc/widgets.php';
require_once ASTRA_THEME_DIR . 'inc/core/theme-hooks.php';
require_once ASTRA_THEME_DIR . 'inc/admin-functions.php';
require_once ASTRA_THEME_DIR . 'inc/core/sidebar-manager.php';

/**
 * Markup Functions
 */
require_once ASTRA_THEME_DIR . 'inc/markup-extras.php';
require_once ASTRA_THEME_DIR . 'inc/extras.php';
require_once ASTRA_THEME_DIR . 'inc/blog/blog-config.php';
require_once ASTRA_THEME_DIR . 'inc/blog/blog.php';
require_once ASTRA_THEME_DIR . 'inc/blog/single-blog.php';

/**
 * Markup Files
 */
require_once ASTRA_THEME_DIR . 'inc/template-parts.php';
require_once ASTRA_THEME_DIR . 'inc/class-astra-loop.php';
require_once ASTRA_THEME_DIR . 'inc/class-astra-mobile-header.php';

/**
 * Functions and definitions.
 */
require_once ASTRA_THEME_DIR . 'inc/class-astra-after-setup-theme.php';

// Required files.
require_once ASTRA_THEME_DIR . 'inc/core/class-astra-admin-helper.php';

require_once ASTRA_THEME_DIR . 'inc/schema/class-astra-schema.php';

/* Setup API */
require_once ASTRA_THEME_DIR . 'admin/includes/class-astra-api-init.php';

if ( is_admin() ) {
    /**
     * Admin Menu Settings
     */
    require_once ASTRA_THEME_DIR . 'inc/core/class-astra-admin-settings.php';
    require_once ASTRA_THEME_DIR . 'admin/class-astra-admin-loader.php';
    require_once ASTRA_THEME_DIR . 'inc/lib/astra-notices/class-astra-notices.php';
}

/**
 * Metabox additions.
 */
require_once ASTRA_THEME_DIR . 'inc/metabox/class-astra-meta-boxes.php';

require_once ASTRA_THEME_DIR . 'inc/metabox/class-astra-meta-box-operations.php';

/**
 * Customizer additions.
 */
require_once ASTRA_THEME_DIR . 'inc/customizer/class-astra-customizer.php';

/**
 * Astra Modules.
 */
require_once ASTRA_THEME_DIR . 'inc/modules/posts-structures/class-astra-post-structures.php';
require_once ASTRA_THEME_DIR . 'inc/modules/related-posts/class-astra-related-posts.php';

/**
 * Compatibility
 */
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-gutenberg.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-jetpack.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/woocommerce/class-astra-woocommerce.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/edd/class-astra-edd.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/lifterlms/class-astra-lifterlms.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/learndash/class-astra-learndash.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-beaver-builder.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-bb-ultimate-addon.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-contact-form-7.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-visual-composer.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-site-origin.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-gravity-forms.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-bne-flyout.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-ubermeu.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-divi-builder.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-amp.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-yoast-seo.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/surecart/class-astra-surecart.php';
require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-starter-content.php';
require_once ASTRA_THEME_DIR . 'inc/addons/transparent-header/class-astra-ext-transparent-header.php';
require_once ASTRA_THEME_DIR . 'inc/addons/breadcrumbs/class-astra-breadcrumbs.php';
require_once ASTRA_THEME_DIR . 'inc/addons/scroll-to-top/class-astra-scroll-to-top.php';
require_once ASTRA_THEME_DIR . 'inc/addons/heading-colors/class-astra-heading-colors.php';
require_once ASTRA_THEME_DIR . 'inc/builder/class-astra-builder-loader.php';

// Elementor Compatibility requires PHP 5.4 for namespaces.
if ( version_compare( PHP_VERSION, '5.4', '>=' ) ) {
    require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-elementor.php';
    require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-elementor-pro.php';
    require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-web-stories.php';
}

// Beaver Themer compatibility requires PHP 5.3 for anonymous functions.
if ( version_compare( PHP_VERSION, '5.3', '>=' ) ) {
    require_once ASTRA_THEME_DIR . 'inc/compatibility/class-astra-beaver-themer.php';
}

require_once ASTRA_THEME_DIR . 'inc/core/markup/class-astra-markup.php';

/**
 * Load deprecated functions
 */
require_once ASTRA_THEME_DIR . 'inc/core/deprecated/deprecated-filters.php';
require_once ASTRA_THEME_DIR . 'inc/core/deprecated/deprecated-hooks.php';
require_once ASTRA_THEME_DIR . 'inc/core/deprecated/deprecated-functions.php';


function add_custom_js_inline() {
    ?>
    <script>
    document.addEventListener('DOMContentLoaded', () => {
        const observerOptions = {
            root: null,
            rootMargin: '0px',
            threshold: 0.1
        };

        const observer = new IntersectionObserver((entries, observer) => {
            entries.forEach(entry => {
                if (entry.isIntersecting) {
                    entry.target.classList.add('visible');
                    observer.unobserve(entry.target);
                }
            });
        }, observerOptions);

        document.querySelectorAll('.edplus_anim-L5I9H8second, .edplus_anim-L5I9H8third').forEach(element => {
            observer.observe(element);
        });
    });
    </script>
    <?php
}
add_action('wp_footer', 'add_custom_js_inline');