No OS Found Error in TWRP: How to Fix

1. Change Slots (For A/B Devices)

If your device does have a dual partition option then make sure that you’re booting to the active slot rather than booting to the inactive slot. The inactive slot doesn’t have the system.img file installed. In that scenario, you’ll just need to switch to the active slot and then check for the results. To do so:

• Go to the Reboot option in TWRP. It’ll now list out the current slot.
  • If it’s an A slot, tap on the Slot B button or select B if the current slot is A.
• Now, you’ll get the No OS error message in TWRP once again.
• Just skip it and perform a right swipe to proceed further.
• Then your device will boot to the other slot > Go to Reboot and select System.
• If your device gets booted to the OS then all is good.

Still, facing the same error? Well, you can follow the next method.

2. Restore Nandroid Backup

If in case, you’ve already created a Nandroid backup before having such an issue then you can easily restore the Nandroid backup file on the device. There is nothing to do extra. To do so: Go to the Restore option in TWRP > Select your Nandroid backup file > Perform a right swipe to restore it. Once it’s done, go to Reboot and select System. Your device should now boot to the OS.

3. Use MTP

You can also mount your device’s storage via TWRP and transfer the firmware zip file which you want to flash directly on your device. Once done, make sure to install it via TWRP. To do that:

• Simply connect your device to the PC via the USB Cable.
• Now, go to the Mount option in TWRP > Checkmark the Data partition.
• Then tap on the Enable MTP button placed at the bottom right corner.
• Your device will now show on your PC > Transfer the ROM zip file into it.
• Next, flash the ROM file as per the instructions mentioned on the XDA Developers blog.
• If you can’t find out any instructions then go to Wipe in TWRP.
• Select Data, System, and Cache partitions one by one > Perform a right swipe to wipe those partitions.
• Go to Install > Select the ROM ZIP file > Perform a right swipe to flash it.
• Once it’s done, you may boot to the newly installed OS via Reboot > System.

Finally, check for the No OS found error in the TWRP Recovery.

4. Use ADB Sideload

Sometimes the data partition may get encrypted and the chances are high that you wouldn’t be able to identify any file on your device which can conflict with such issues. It’s better to use ADB sideload method by following the steps below to install the Custom ROM on Android.

• Download and extract the Android SDK Platform Tools on your PC.
• Transfer your ROM file to the platform-tools folder where it’s installed.
• Go to Advanced in TWRP > Select ADB Sideload.
• Now, perform a right swipe to start the sideload process.
• You’ll have to connect your device to the PC via a USB cable.
• Next, go to the platform-tools folder address bar > Type cmd and hit Enter to open Command Prompt.
• Then just type in the below command and hit Enter to flash the file via sideloading: [Replace file.zip with the actual file name and add .zip at last]

adb sideload file.zip

• Now, go to the Reboot section in TWRP > Select System.
• If your device is able to boot to the system successfully that means the No OS Found Error in TWRP issue has been fixed.

5. Flash Stock Firmware

If none of the methods worked for you then make sure to flash the stock firmware via Fastboot Commands or device-specific tools such as SP Flash Tool, Mi Flash Tool, Android Flash Tool, etc. To do so:

• Go to Reboot in TWRP > Select Bootloader.
• You’ll again get the No OS error message > Skip it and perform a right swipe to confirm.
• Your device will now boot to the Fastboot Mode.
• Now, you’ll have to flash Stock Firmware via Fastboot Commands according to your OEM or model number.
• Have some patience and perform all the steps correctly to boot your device into the newly installed OS.

That’s it, guys. We assume this guide was helpful to you. For further queries, you can comment below.