First, To login in your account, you must use correct login link:
The link for FREE version is https://free.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 same password as you wrote when signing up.
If any of these tips doesn't work, please contact our email@example.com