Let's try to figure it out, and get more data here.
Links are dead but if we have bigger problems those would go first. Do you have the resource tree in the dashboard? You should have 3 sections on the left side, with the resource tree, the middle part has templates, chunks and snippets and so on, and then the file system where you can find css files and so on.
I think given the recent problem you will need to upgrade before anything else. This recent situation has been unusual and serious, so upgrade asap please.
Now links are provided in the header, when Modx is configured correctly, like this:
<base href="[[!++site_url]]" />
But check your error log to see what's going on, your probably throwing an error and redirecting to front page.
Also the advice about friendly urls or htaccess could be right...did their hoster change anything recently? We need the error log