conflict with enfold theme

I have been using this theme since 2018 without any problems. (API Key zeqx0qgytoylgjcbxxnqm6qtbq235avq)
Now I am having a conflict problem with WordPress with these error details:

An E_COMPILE_ERROR error was caused in line 49 of the file /var/www/vhosts/acousticguitarworkshops.com/httpdocs/wp-content/themes/enfold/config-templatebuilder/avia-shortcodes/chart/chart.php. Error message: Access level to avia_sc_chart::shortcode_insert_button() must be public (as in class aviaShortcodeTemplate)

Here’s the full WordPress automated message:

Hi.

WordPress, starting with version 5.2, has a built-in feature that detects when a plugin or theme causes an unrecoverable error on your site and alerts you with this automated email.

In this case, WordPress has encountered an error with your theme, Enfold.

First, go to your website (https://www.acousticguitarworkshops.com/) and check for visible problems. Next, go to the page where the error was found (https://www.acousticguitarworkshops.com/wp-admin/) and see if there is any visible problem.

Contact your host to request assistance for a more thorough investigation of this problem.

If your site appears corrupted and you cannot access your bulletin board normally, WordPress now has a special “recovery mode.” This allows you to securely access your bulletin board to check what is wrong.

https://www.acousticguitarworkshops.com/wp-login.php?action=enter_recovery_mode&rm_token=kJcm3HlNJlUAgYPYO7i8Le&rm_key=dnkROPkHAH4Gw3W825NaPK

To keep your site secure, this link will expire in 1 day. Don’t worry about this: a new link will be sent to you if the error reoccurs after the expiration.

If you are looking for help with this problem, you may be asked for some of the following information:
WordPress version 6.1.1
Active theme: Enfold (version 5.2.1)
Current Plugin: (version )
PHP version 8.0.24

can you help me?

many thanks, Raffaella