I've got a multisite at thedesig****.com & have an issue with a subsite at kalutrainingandco*****y.co.uk/contact-kalu/
There should be a forminator form but it has display: none set in the inline css. This was fixed adding a bit of CSS.
But once I submit the form, it displays a 500 error. This was saved in the debug.log:
PHP Fatal error: Class 'Forminator_CForm_View_Page' not found in /wp-content/plugins/forminator/library/helpers/helper-fields.php on line 400
Also on that page there should be a google map but it doesn't show it. no JS errors.