Reboot your Kindle Paperwhite using the following reset steps:
- Press and hold the power button until either a power dialog box appears or the screen goes blank.
- Continue holding the power button for 40 seconds, then release.
- After a few seconds, the charge indicator light turns back on and the device reboots.
Additionally, swipe down from the top of the device screen and choose the Sync option, and then check if the device is ready for an update.
In the possibility that it’s Wi-Fi related:
- Go to Wi-Fi networks and “Forget” your Network.
- Then, reboot your Wi-Fi router by unplugging it from the power source for about 30 seconds.
- While the router is unplugged, power off your Kindle Paperwhite.
- When the router has completely reconnected to the Internet, power the Kindle Paperwhite back on and reconnect to your Wi-Fi network.