Chapter 5 — Aftermath
If you've successfully downgraded to Android 11, here are some tips and tricks to enhance your experience:
The MSM tool ignores any software locks. Even if you have a corrupted bootloader or a disabled touchscreen, this method will resurrect your phone to stock Android 11. It is the only way to downgrade if you have a hard brick. downgrade oneplus 9 to android 11 exclusive
OnePlus 9 (LE2110, LE2111, LE2113, LE2115, LE2117) Target OS: OxygenOS 11.2.10.10 / 11.2.20.20 (Android 11) Prerequisite: Unlocked Bootloader (Mandatory for cross-version rollback)
To downgrade your to Android 11 (OxygenOS 11), you can follow two primary methods. Both methods will completely wipe all data Chapter 5 — Aftermath If you've successfully downgraded
: OxygenOS 12 removed the "Local Upgrade" option from settings. You need to download and install the OPLocalUpdate_For_Android12.apk to restore this feature. Prepare the File : Move the downloaded rollback package (.zip) to the root directory of your phone's internal storage (not inside any folder). : Ensure the file extension is strictly . If it ends in , rename it to remove the Execute the Rollback
Wait for the progress bar to reach 100%. Step 4: Initial Device Setup OnePlus 9 (LE2110, LE2111, LE2113, LE2115, LE2117) Target
Official links sometimes become unavailable. In that case, community‑hosted mirrors are your best bet, but always verify the file’s MD5 hash if possible.
: Keep your phone charged to at least 50% to avoid a mid-process shutdown.
Extract the downloaded firmware using password: . Open the firmware folder where you extracted the files.
Sometimes, flashing an older firmware can cause sensor incompatibilities if the persist partition was corrupted. Perform a full factory reset from the phone’s recovery mode. If the problem persists, you may need to re‑flash the firmware using the MSM tool again, ensuring you have the exact correct package for your region and sub‑model.