If your member is having issues login into the member portal, setting up their password or resetting their password, there are a few simple troubleshooting steps you can go through. These steps will resolve 90% of the issues with portal logins.
Account End Date
Check the end date on the account. If the end date is in the past, contacts on the account won't be able to log onto the member portal.
Contact End Date
I you've added end date as a field on contacts, check the end date on the contact. If the end date is in the past, the member won't be able to log onto the member portal.
Email Address is in the Database Multiple Times
Using your universal search in Operate, search for the member's email address. The email being in your database multiple times may lead to Operate associating the login attempt with the wrong contact/account. Make sure the email address is only in the database once.
No Last Name
Going back to the contact, make sure that the contact has a last name. Contacts with an empty last name field will experience issues. As default, the last name field is not mandatory when adding/editing a contact. To avoid forgetting to add a last name and having the member run into login issues, you can make the last name field on contacts mandatory. Here's how.
Make Sure the Member was Invited
Under the member's activity history, make sure the member received an invite to the portal. If this is not the case, invite the member. When in doubt, you can re-send the invite.
Side note: you can automatically invite new members to the portal up on license activation. Your customer success manager can help you set this up and you can find more information here.
In many cases, you want the member to have Admin access to the portal. Especially the initial user, as this allows them to add new members under the same account to the portal without you having to add them.
You can find the details on portal access levels here.