Warframe will be upgrading its servers April 17 - 18! This upgrade will be happening LIVE all day, both days, but should not affect the game or website. 

We hope the upgrade will prevent future server issues and we greatly appreciate your patience last week during our “growing pains.” If you do experience log in problems, please wait a couple of hours and try again. 

Check out this forum post for the full scoop: https://forums.warframe.com/index.php?/topic/30270-notice-april-17th-8-am-edt-12-pm-udt/