First, to log in to your account, you must use correct login link:
If you registered after May 1st 2018, your log into the FREE 2.0 version is https://app.nihaocloud.com/accounts/login/
This link is also "server address" when setting up Seafile drive/client/app in order to sync your files with your devices.
Second, make sure you don't write your password/email address with extra spaces.
Third, make sure you type the same password as you wrote when signing up. ( This happens more often than one would think).
Fourth, try a different browser & clean your cookies + browser cache. Sometimes other passwords get cached in the browser...
If any of these tips don't work, please contact our firstname.lastname@example.org