ZC 1.5.7
Bootstrap template with OPC

I am getting the following error when trying to preview "checkout email":
[25-Oct-2022 02:22:23 UTC] PHP Fatal error: Call to undefined function opc_load_legacy_language_definitions() in /includes/languages/english/checkout_process_guest.php on line 12

[25-Oct-2022 02:22:23 UTC] Request URI: /sweety/index.php?cmd=preview_email, IP address: 76.103.115.109
--> PHP Fatal error: Call to undefined function opc_load_legacy_language_definitions() in /includes/languages/english/checkout_process_guest.php on line 12.
i am also getting this error when trying to preview "welcome email"

[25-Oct-2022 02:26:21 UTC] PHP Fatal error: Call to undefined function opc_load_legacy_language_definitions() in /includes/languages/english/create_account_register.php on line 12

[25-Oct-2022 02:26:21 UTC] Request URI: /sweety/index.php?cmd=preview_email, IP address: 76.103.115.109
--> PHP Fatal error: Call to undefined function opc_load_legacy_language_definitions() in /includes/languages/english/create_account_register.php on line 12.
Any assist on resolving these2 erros wouldbe more than appreciated.

All the other options work great.

Thank you