Fatal error: apply_filters() conflict in email Customizer plugin

I use a plugin Woocommerce Email Customizer but recently the email refused to work giving PHP Error email cannot display

  1. ***/public_html/wp-content/plugins/woocommerce-email-control/ec-email-control.php(1059): apply_filters()

  2. ***/public_html/wp-content/plugins/woocommerce-email-control/ec-email-control.php(1005): WC_Email_Control->ec_style_inline_for_old_wc()

  3. ***/public_html/wp-content/plugins/woocommerce-email-control/pages/ec-preview-page.php(195): apply_filters()

  4. **/public_html/wp-content/plugins/woocommerce-email-control/ec-email-control.php(562): require_once(‘//*/…’)

How do I tackle this and what does this error mean

There’s no more support for this plugin or update as developer is gone!

I have tried to rewrite the hook function but it just seems I’m not getting it