Please add your clan’s information to our thread in the Bug Report forum:
Unfortunately we do not have a solution / response from Blizzard as yet. My clan has been down for 2 weeks now.
And for everyone else reading here - this is not an individual problem. With 319045 the clan is down for everyone in the clan, no leaders, officers, members can see it. Hence it is not solvable by leaving communities / groups / the clan itself (you will not be able to re-join, as no officer can see the clan or request).