When the form is submitted a blank Thank You page is shown

The form finally calculates and accepts someone's payment!!!!!!! However the screen just goes blank after the submit. no message that payment was acce

I am unable to test your form because it has the payment field, so I have cloned your form and made several tests but I could not replicate the issue you reported. When I submitted my cloned form I was redirected to this webpage - www.letloveinternational.org/thankyou 

That is the page you set as the redirect URL.

Were you able to resolve the issue? 

Also please note that the redirect URL will not be shown when the form is tested in Preview mode. In the Preview mode, the Redirect URL will be blank. You have to open your form in a separate tab, like you user would, to properly test it.