Links are broken

So on my website at https://www.comparecrm.com/crm/crm-news/ , the about, archives and the title links doesn’t work. I have checked all of the themes and plugins and they seem to work fine. I am not sure exactly what is wrong with it, if someone can point out some basics that I should trouble shoot for, that would be great.

Yes, I went into Manage -> Pages to make sure there is an about page and I did put content in, but it always comes up with a 404 error.