When this problem happens, please check your account which maybe had been expired. eg:u30479. The ID should be contained in the "Welcome to Intel® DevCloud for the Edge" email. If the account is expired, please register.
If you already have a new account and log in via that link. When the problem happens, please clear the cache of IE/Chrome browser, then click "home page", in the next page click“Start My Server", it will fix the problem.