Why I cant open my clan page.

Its cause they are changing up the clan page. Just wait and they'll have it fixed soon.

It's not a problem on the user side, it's most likely a problem with the servers or some what. It could be the clan page update that has been talked about for a little bit, but it could just simply be a glitch. Nothing is official [for example, the reason why the page is down] until it's made known, or the community has official confirmation.

Just be patient, something will happen soon, regardless of if updates are coming. Sorry for inconveniences.