The updated iOS 9.3 addresses an issues when updating to iOS 9.3 on older devices such as iPhone 5s and earlier or iPad Air and prior, users were asked to enter their Apple ID and password, and in cases where users couldn't remember their password the devices became stuck in an inactivated state.
The updated iOS 9.3 is now rolling out as a free update through Software Update or can be downloaded via iTunes to all supported older iPhone, and iPad devices.