500 error when submit step 1 form

Hi there,
I have been using Multiline files upload for contact form 7 and it have been running as we expect until we update the WordPress from 5.2 to 5.7.
What happen is it generate a 500 erro on admin-ajx.php page when trying to submit the form’s step 1.
———–Chrome Browser error message–
admin-ajax.php:1 Failed to load resource: the server responded with a status of 500 (Internal Server Error)
cf7mls.js?ver=2.5.4:406 Validation error
cf7mls.js?ver=2.5.4:410 Validation complete

——debug log———-

[23-May-2021 11:13:12 UTC] PHP Warning:  Missing argument 3 for mfcf7_zl_multilinefile_validation_filter(), called in /home/public_html/wp-includes/class-wp-hook.php on line 292 and defined in /home/public_html/wp-content/plugins/multiline-files-for-contact-form-7/multiline-files-upload-for-contact-form-7.php on line 245
[23-May-2021 11:13:12 UTC] PHP Notice:  Undefined variable: args in /home/public_html/wp-content/plugins/multiline-files-for-contact-form-7/multiline-files-upload-for-contact-form-7.php on line 256
[23-May-2021 11:13:12 UTC] PHP Fatal error:  Uncaught Error: Call to a member function get_contact_form() on null in /home/public_html/wp-content/plugins/multiline-files-for-contact-form-7/multiline-files-upload-for-contact-form-7.php:258

Thank you and any suggestion would be appreciated.

• This topic was modified 3 years, 6 months ago by jackysoaringhealth.

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