If there is a red status bar as exampled in the image below, and the device is experiencing various errors when trying to run a transaction - it may be that Battery Saver has been toggled. This will prevent the device from operating as normal because some necessary hardware may not be getting enough power to perform whatever function is necessary to run a transaction.

Note: The red status bar along the top and red navigation bar indicate Battery Saver is enabled.

1. To disabled this, pull down from the top to reveal the Quick Settings tiles. Tap the one with the icon as shown below.