cookies error trying to login

i’ve created two new sites. when in ‘my sites’ i can see both in admin panel. the first site is the primary site. i can visit and enter dashboard on the first site. i can visit but cannot enter dashboard on the second site, i get the ‘wp login’ page instead. when i try to log in i get an error message stating ‘ERROR: Cookies are blocked or not supported by your browser. You must enable cookies to use WordPress.’ this error appears nowhere else and cookies are enabled in chrome.

my first question, why do i have to login? the second, the error message.