There does seem to be a problem with the front page not linking but you can access via this news article from Lockers.

rlhttps://www.wiganwarriors.com/WContent.aspx?id

Now working fully.

I am trying to get tickets for the World Club Challenge from the Wigan site and it keeps coming up with the error page. I have bought from there before and logged in but it still keeps coming up with an error. If I ring up the ticket office tomorrow can I specify seats that I want, like on the site, or do they just allocate them?

I'm sure that if you know which seats you require (and that they are available), then they will allocate these for you.