Error in form-field-settings.php on line 49

When we open the form builder screen, this error message appears and does not display form fields.

We want to buy the PRO version to export the data registered in the form.

Parse error: syntax error, unexpected ‘=’ in / home / storage / 2 / e1 / 76 / showadecor / public_html / wp-content / plugins / contact-form-add / admin / views / backbone / form-field-settings. php on line 49