Uncaught TypeError: Cannot access offset of type string on string

Hello everyone, since few days, the wp installation running MainWP dashboard is not more working, I receive an email with this error:

Uncaught TypeError: Cannot access offset of type string on string in /home2/scariann/public_html/riccardo/mainwp/wp-content/plugins/mainwp/class/class-mainwp-api-handler.php:72
Stack trace:
#0 /home2/scariann/public_html/riccardo/mainwp/wp-content/plugins/mainwp/class/class-mainwp-system-handler.php(740): MainWP\Dashboard\MainWP_API_Handler::check_exts_upgrade()
#1 /home2/scariann/public_html/riccardo/mainwp/wp-content/plugins/mainwp/class/class-mainwp-system-handler.php(769): MainWP\Dashboard\MainWP_System_Handler->check_upgrade()
#2 /home2/scariann/public_html/riccardo/mainwp/wp-includes/class-wp-hook.php(310): MainWP\Dashboard\MainWP_System_Handler->pre_check_update_custom(Object(stdClass))
#3 /home2/scariann/public_html/riccardo/mainwp/wp-includes/plugin.php(205): WP_Hook->apply_filters(Object(stdClass), Array)
#4 /home2/scariann/public_html/riccardo/mainwp/wp-includes/option.php(2018): apply_filters(‘pre_set_site_tr…’, Object(stdClass), ‘update_plugins’)
#5 /home2/scariann/public_html/riccardo/mainwp/wp-includes/update.php(391): set_site_transient(‘update_plugins’, Object(stdClass))
#6 /home2/scariann/public_html/riccardo/mainwp/wp-includes/update.php(1020): wp_update_plugins()
#7 /home2/scariann/public_html/riccardo/mainwp/wp-includes/class-wp-hook.php(308): _maybe_update_plugins(”)
#8 /home2/scariann/public_html/riccardo/mainwp/wp-includes/class-wp-hook.php(332): WP_Hook->apply_filters(NULL, Array)
#9 /home2/scariann/public_html/riccardo/mainwp/wp-includes/plugin.php(517): WP_Hook->do_action(Array)
#10 /home2/scariann/public_html/riccardo/mainwp/wp-admin/admin.php(175): do_action(‘admin_init’)
#11 {main}
? thrown

Details about system are the following:

WordPress version 6.1.1
Theme: Twenty Nineteen (versione 2.4)
Plugin: MainWP Dashboard (versione 4.3.0.2)
PHP version 8.0.25

I tried to reinstall the plugin but nothing happened.

Please let me know if you need further info in order to troubleshoot this issue.

Thanks in advance