This is the only safe way to get the correct verified image.
If the issue persists after following these steps, there may be a hardware failure with the switch's Flash storage module. Contact Huawei Technical Support (TAC) for hardware replacement options. huawei s7721u recovery image verify failed link
A failing internal storage (eMMC) can sometimes cause image verification to fail because the data cannot be read correctly. This is the only safe way to get the correct verified image