How to fix a checkout page load error on my website?

[iasthai_og]

Hi, I hope someone can help.

I'm currently editing my site and when I go to checkout page this error comes up:

Failed to load the page

This page is not compatible with the editor due to one of the following issues: 

- Page is redirecting to an unsupported URL

- Page failed due to load error 

I found another thread on here with the same issue and followed the steps on my 3rd party domain provider (go daddy) but it's made no difference. I also tried to acces from both laptop and mobile. 

Is anyone able to help or take a look at my site please? Thank you in advance