App error 523 occurs due to installed application that fails to start and may corrupt operating system of BlackBerry device. The easiest way to resolve this error is to remove the application that is causing problem and reinstall the operating system. If you are not confident enough to do it yourself, take your device to repair store. But they would certainly take time to solve this problem plus if your device is out of warranty, you have to pay them. Things required fixing App Error 523 Make sure you have following things before you start repairing error at own. 1) BlackBerry Device 2) Active Internet Connection 3) BB data cable to connect with PC 4) BlackBerry Desktop Manager and of course PC 5) Fully charged BlackBerry Battery 6) IE (Internet Explorer) to download latest version of firmware of BB device. The steps outlined below would fix App Error 523. First of all make sure you have active Internet Connection in order to download latest version of Blackberry Firmware. In fact BlackBerry Desktop manager would make the entire process easier for you, if you have one installed on PC. After downloading latest version of BlackBerry firmware, try updating your device by connecting it to PC using BB USB/data cable. Updating device would take time, you need to be patient and wait for update to finish. 2. During update process, you need to enter Blackberry password if asked | Click on Next 3. Now select the applications that are needed to load on your BlackBerry device 4. Remember to choose automatically backup blackberry device | Click on Next 5. Now click on Advanced button | Remove all application data (mark both application data and currently installed applications) | Click Next 6. Enter your email Address on next screen and Click Next Again 7. Now click on Finish. It would take time 8. After process is finished, unplug your Blackberry device from PC 9. Start browsing