It seems that this problem is common in firefox community. So first of all I basically tried all default troubleshooting steps such as dealing with cookies (turning off, tuning on, exceptions), cleaning data, cleaning cache, security settings, etc etc, even though I am on freshly installed firefox. So lets see now, problem is with https://vk.com/ website. It works until processing my login info. After I enter necessary credentials, it reloads and just produces infamous error. Network monitor displays loop of login.vk.com domain migrating cookies to login.vk.ru which restores them and then finally trying to open actual account php page starts the loop anew. Well until NS_ERROR_REDIRECT_LOOP stops this shamelessness. Resetting all browser data back, just enables me to enter my credentials again and the same process starts again. I can access this website from the same network from different browsers from different devices and operating systems. Currently I encounter this problem on recently installed Arch linux, with basically dwm and firefox, and since I had very rough time with how unpredictable this system were so far, I don't know how much it is browser issue, so I think I should mention it. Thank you in advance.