Yikes! Just installed Gravity Form 2.3.6.4 and a white screen displays when I click ‘New Form’ . Is a file missing?
I don’t believe so. But it is possible your download was corrupt. I would try downloading the latest v2.3.6.6 from here https://www.gravityforms.com/my-account/downloads/
Without knowing the error that is causing the white screen, it’s hard to say what the cause is. If you have access to the server error logs, or can use WP_DEBUG to log or display the error yourself. then we can help you with the actual error message. I would try installing the latest though and see if you have the same issue.