BBM Users at CrackBerry’s forums have been complaining of their inability to switch their BBM account back to old BlackBerry devices running BlackBerry’s operating systems.

The problem experienced is that the server does not allow them access contacts, groups, and channels after trying to switch back to a BlackBerry OS device.

In case if you are still the type that hop around between BlackBerry OS devices, however, if you jump from a BlackBerry device to an Android-powered BlackBerry (or otherwise), iOS, or Windows device, you will not unable to successfully access BBM on a legacy BlackBerry device.

”We have recently completed changes that prevent users from switching their accounts from an Android, iOS, or Microsoft device to a BlackBerry 10 or BlackBerry OS device. Also, in addition, BBM Enterprise users will no longer be able to switch their BBM Enterprise account to a BBM consumer account on an Android, iOS, or Microsoft device.” - BBM Product Management.

According to CrackBerry the problem of BBM getting “stuck” on latest platforms arises from BlackBerry handing over the consumer BBM service to Emtek. Therefore, if you still have BBM on an old legacy BlackBerry device, it’s suggested that you don’t move your BBM account, but instead create a new one when swapping to the newer platforms and leave your original account on the BlackBerry phone.

http://www.tellforceblog.com/2017/09/you-are-no-longer-allowed-to-switch.html