The Nexus 7 is a powerful tablet and performs quite well on high-end usage. However, it is not devoid of common bugs and errors as seen with other Android tablets. Some users experienced No SIM Card errors when they tried to insert the SIM card into Nexus 7. Whereas, others have seen SIM Card Added message with a prompt to restart the device. Either message is indication that SIM has not been properly inserted into the Nexus 7’s SIM port or that the device has not detected the SIM card.
To fix the error, reboot the Nexus 7 device by long pressing the Power button – ignore the prompt to shutdown and just wait for the device to restart itself. Alternatively, pull down notification panel, tap on the Airplane Mode icon, and restart the Nexus 7. If that doesn’t fix the issues, navigate to Settings > Wireless & Networks > More > Mobile Networks > Access Point Names and ensure that you have chosen the right network provider in accordance with the SIM card carrier.
If any of the methods won’t fix the SIM card error on Nexus 7, remove the battery of the device in order to verify it’s not your SIM card’s fault. SIMs from US carriers will not work on European version of Nexus 7 and vice versa, so it could also be the SIM causing the SIM Card Added error message to pop up on your device.
Another error message that users of Nexus 7 see from time to time is the Camera Error. Can’t Connect To The Camera. pop up on the Camera app. To fix that error on Nexus 7, navigate to Settings > Apps, scroll to All Tabs, and open the Camera app. Then, tap on Clear Cache and reboot the Nexus 7 device by pressing and holding down the Power button. Additionally, go to Settings > About Tablet > System Updates and ensure that the camera app on Jelly Bean is up-to-date.
Users say that the most annoying bug on Nexus 7 is the flickering screen. It is seen that the screen flickering bug on Nexus 7 occurs most of the time when the brightness is on the lower side. To fix that, pull down the notification panel on the device and select Brightness. Then turn off Auto-Brightness and then adjust the device’s brightness to more than 40 percent.