One of my pages disappear when I preview the prototype.

Hi Israa24089346t5vc,

Hope you are doing well and thanks for reaching out to us.

As per the screenshot you have shared, I can see the viewport size is 1, please give viewport size same as the height of the artboard to view the artboard completely in preview window.

Hope this will help and do reach out to us if you have any further queries.

Thanks,

Chaitanya