When I was uploading my images to my wordpress blog, the page shows my upload fails. And then when I refresh my webpage, it shows Error data base message. Then, after about one day when I re-open my website, it shows Error 521.
I have already looked through those Erro 521 posts, but I don’t know how exactly I need to check firewall whitelist or how can I fix it. Sorry I am a beginner on these.
You need to contact whoever is hosting your site. WordPress can be hosted on wordpress.com or the software can be hosted on many other web hosts. Whoever you pay for web hosting / server is who you will need to contact.