When I open the site it always gives me an error why?

Hi, Omar Rdwan!

We'd love to have a better understanding of the issue you're running into. Could you please submit a support request in our Help Center? Here's the link: http://khan.co/KA-support. 

Thank you for being a part of Khan Academy!

Are you using a mobile device that has an IOS lower than 16.6, or an Android that’s lower than 9.0 (pie)? I also ran into that error, and it turned out that it was because my iOS was to low.