You have forgotton a user password set on Polaris are then unable to sign into the unit.
There are two hotkeys which can used on the unit which will be two forms of reset:
Backspace-F1-Stop - Remove Polaris settings, reboots to Android welcome screen.
F1-Play - Will remove the Google play partition.
The second reset for the Google play partition may be needed if the user is still prompted for a password. Therefore all data including Google related settings will be lost.
For users wishing to use power-on password the following warning is shown in the manual: setting a power-on password:
"WARNING!! It is imperative that you create a password that you can easily remember, or that you store in another location for easy retrieval!
Due to Android security safeguards, HIMS are not able to send unlock codes as has been the case with older BrailleSense models. If you set a password using this function, or using the Android system settings, and you are not able to remember or retrieve it, it will be necessary to send the unit to HIMS/SELVAS for unlocking, during which, all data will be lost. As remembering and retrieving personal passwords is the responsibility of the customer, any costs associated with transporting and/or unlocking the unit are also the responsibility of the user."
To restore the unit the Polaris will have to be shipped to HIMS to be unlocked, in that process customer data cannot be restored and so the customer should be forwarned data loss will certainly occur.