A FAT32-formatted SD card and the official S7721u firmware (often an UPDATE.APP file). Process: Create a folder named "dload" on the root of the SD card. Place the UPDATE.APP file inside that folder.
If verification fails on the stored image, reload from TFTP: huawei s7721u recovery image verify failed link
If none of these software solutions work, it may indicate a hardware failure, and you should contact a Huawei Service Center for further assistance. HUAWEI Global for your specific region? How to Fix Huawei Recovery Image Verify Failed Error A FAT32-formatted SD card and the official S7721u