You can't fix it.
You are likely connected to a network that is blocking facebook pages. This is common when you are connecting from any business network including certain free hotspots. The only thing you can do request access to facebook.
On the other hand there is a small chance (a higher chance if you are at home) that your browser has been hijacked and you are being redirected to a different webpage. If that is the case you can use "HiJack this" OR take it to computer experts to fix the issue.