This issue occurs when a user has an active Identity session open that for an Identity account that is not linked to the Paycircle account they're trying to log into.
Users can resolve this issue by logging out of Identity first:
Open the Access Identity portal and in the top right, click Sign Out.
If the prompt appears, click Sign out of your Access account.
Navigate back to Paycircle and re-attempt the login.
If this does not work, the user may have linked their Paycircle user account to a different Identity account than they want to use. You can remove the linked Identity account for them at any time with the unlinking function: