Starting with Android 5.0 Lollipop, Google moved to a new runtime called ART (short for Android Runtime). This change was done to ensure that apps are optimized the moment they are installed. In the previous versions of Android, an old just-in-time Dalvik Runtime was used. Apps and games were optimized at the exact time that you opened them. Instead of optimizing apps over and over again, ART optimizes them only once and saves on the processor cycles as well as battery life. Unfortunately for OnePlus users, this has become an issue. With ART, the “Optimizing Apps” procedure is painfully long. It is also more battery intensive, so if your OnePlus device is stuck in an Optimizing Apps loop, you may end up with an overheated and low battery phone sooner than you can imagine. As such, this is a critical issue, one that needs to be fixed as soon as possible.

Recommended: Steps to Manual Update OnePlus 2 to Oxygen OS 2.2

3 Ways To Fix OnePlus Optimizing Apps Issue on Boot Up

1. Remove And Reinsert Your MicroSD Card

One of the easiest ways to fix this issue on your OnePlus device is by removing the microSD card and rebooting your phone. Some apps installed on the SD card may be pushing the apps optimization process into a loop, so removing the microSD card and letting the phone complete it will help. Once you have done that and your OnePlus phone has booted into Android, insert the microSD card and move all the apps installed on it back to the phone’s internal memory. To identify which app is causing this issue, you may have to use a trial and error method, but it may take a while.

2. Wipe Cache Partition

One slightly complex way that many users have reported to work is wiping the cache partition. It has worked for me on my Nexus 5 multiple times, too, so I can testify to it. All you have to do is:

Press and hold both the volume buttons and the power button at the same time.When the phone vibrates and boots into the bootloader, release the buttons.Use the volume rocker to highlight the “Recovery” option in the bootloader.Press power button to confirm booting into Recovery.Once you are in the Recovery, use the volume button again to highlight Wipe Cache Partition. Press the power button to confirm.Once the wipe is complete, select Reboot into System and confirm.

This process can take a while, depending on the number of apps you have on your OnePlus device. Your phone will start optimizing apps once again but it won’t get stuck now.

3. Factory Reset Your OnePlus Phone

As a last resort, you may have to factory reset your OnePlus device. No one likes to lose their data like this, but this will fix your OnePlus phone. Since you can’t boot into Android, you will have to do this from the recovery.

Press and hold both the volume buttons and the power button at the same time.When the phone vibrates and boots into the bootloader, release the buttons.Use the volume rocker to highlight the “Recovery” option in the bootloader.Press power button to confirm booting into Recovery.Once you are in the Recovery, use the volume button again to highlight Wipe Data / Factory Reset. Press the power button to confirm.Once the wipe is complete, select Reboot into System and confirm.

Warning: This will factory reset your OnePlus device. All your data will be lost in this process – messages, photos, videos, apps, games etc. Let us know if this fixes your OnePlus device issues.