cant logg in to my account error 404 but any other accounts work

[schmiddiline]

Hello there, 
So my Problem is... 
I have 2 Accounts the Main Acc i wanted to Logg in and the "Old" one that work. now i want to Logg in, on my windows desktop programm but there is the error 404. Than i look for some posts "what is error 404". 
I saw that is an error for my system problems and that my spotify or my system gets a virus or something like that so mybe i havent a antimalware or anti virus Programm but if thats the Problem i cant logg in to any Accounts on my pc so... why i cant logg in to my main Acc

[schmiddiline]

sry for my English i am from Germany and i learned english only from school.