This can happen on Android devices if you enabled Automatic date and time within the system settings, then removed the battery and clocked in/out before having data connectivity. Most times the device will correct itself when it comes back online with data connectivity.
It's possible that your phone has a glitch, or defaulted to the manufacturer date. Sometimes this can be due to an expired internal clock battery (called a CMOS battery) or physically removing the battery and not allowing enough time for an internet connection to re-synchronise with the world clock.
The device has another app that isn't correctly releasing the camera, especially if that app crashed.
Our application crashed whilst using the camera, failing to release the camera properly.
It is not normal for our application to crash, and could indicate other issues such as a device issue or incompatibility issue with a non-standard or very old model.
To try to resolve this issue:
First step is to restart the device. In many cases that can temporarily resolve the issue. If you know that our app did crash, causing the camera to fail until restart, then please alert us to this issue.