You're here because resetting the password doesn't work, and you've already confirmed they're logging into Aspen using the right URL and the right credentials. If they still can't log in, their account and/or password might have expired. This is applicable to all types of users - student, teacher, family.
1) Go to District view, Admin top tab, side tab Users:
2) Find the problem account and click into it. The Zzdemos just have no luck:
3) Check their account and password expiration dates, circled below. Yup, looks like it's expired.
4) Change it to a date in the future, then save:
5) Let them know they can log in now.
5a) If they haven't setup password recovery, the below window will pop up when they try to log in. If they want to set it up later, they can just click on Later and it will take them into their account: