Huawei devices use a mechanism. If you are trying to "repack" a recovery image (e.g., to add custom tools), the device will reject it unless the bootloader is unlocked. Repacked images usually lack the required RSA signatures, triggering the "verify failed" message immediately upon boot. How to Fix Huawei Recovery Image Verify Failed Error
If eRecovery fails, you must flash the stock firmware manually via an SD card. an SD card to Create a folder named in the root directory. Place the official UPDATE.APP file inside the Power off the device. Press and hold Volume Up + Volume Down + Power simultaneously. huawei s7721u recovery image verify failed repack