Back in October, Samsung confirmed that they are skipping Android 4.2 Jelly Bean update for the Galaxy S3 and going straight for Android 4.3. Although the company started rolling out the update, unfortunately that will have to wait a little bit longer as the update is apparently stopped due to some bugs.
According to various reports, users are facing problems such as poor battery life, WiFi connection and completely locked handset, after which the restart is necessary. There are several more problems reported that needed to be fixed. However, the update for Galaxy S4 is on its way and won't face any delays.