If a main page, a page "Settings" and a page "Firmware" open normally, but other pages are unavailable, then a probable reason is incorrectly ended last software update. A software update is performed in 2 steps: first, software of a device is updated, then a device will reboot. Afterwards, firmware resources are updated, including a content of web pages. When the first step of software is completed and the second step is not, only several web interface pages remain active. They allow to retry software update process.
What Do I Need to Do?
Retry updating software through a web interface and make sure both steps of update are completed successfully:
The next message must appear: "Software update is completed successfully!"