In Whiteboard version v.1.42.4, v.1.43.6, v.1.45.2, users are required to "Enroll the Whiteboard" with an Entity account before updating the app (v.1.45.2) via OTA.  Non-Entity accounts will encounter enrollment issue (see the image below).

Entity user may enter their school email to enroll, or an Entity admin user will be able to 

When users see this message: "This email does not belong to an Entity. Pleas verify the email and try again,"
please first contact school IT and enroll the Whiteboard with an Entity account.

 Alternatively, the school IT can proceed the app update via myViewBoard Manager via clicking this link. 

Please note that the Open version of APK is for devices other than Viewsonic ViewBoards; the app apk for Viewboard is only available in the firmware and via OTA updates.