What should I do with App Error 523?

App Error 523 is a software hiccup usually caused by a 3rd-party application that is not compatible with the BlackBerry device OS.
Follow the below steps to get rid of this error message:

1. Take the battery out and put it back in after 30 seconds or so

2. While the device is rebooting (or while the hourglass is still spinning), plug it into the PC

3. Then open the application loader and remove the 3rd-party application that’s causing the issue

4. Worst-case is when you need to wipe the device using JL_Cmder. Follow the instructions here: How do I wipe the BlackBerry using Jl Cmder?
Thanks to John Clark from BlackBerryForums for the tip!

1.44 Inch USB 2.0 Type- C Voltmeter Ammeter Battery Charge Measure Cable Tester picture
1.44 Inch USB 2.0 Type- C Voltmeter Ammeter Battery Charge Measure Cable Tester
$5.0 Vintage Columbia Electric Tong-Test with 4 Scales in Case picture
Vintage Columbia Electric Tong-Test with 4 Scales in Case
$0.99 NEW LCD Digital Multimeter Volt AC DC Tester Ammeter Ohmmeter Meter BG picture
NEW LCD Digital Multimeter Volt AC DC Tester Ammeter Ohmmeter Meter BG
$8.17 NEW LCD Digital Multimeter Volt AC DC Tester Ammeter Ohmmeter Meter BG picture
NEW LCD Digital Multimeter Volt AC DC Tester Ammeter Ohmmeter Meter BG
$8.17 Battery Tester Current Voltage Doctor Charger Capacity Meter Ammeter Diagnostic picture
Battery Tester Current Voltage Doctor Charger Capacity Meter Ammeter Diagnostic
$9.95