Welcome to the world of — Samsung’s most effective, and most frustrating, implementation of Android Verified Boot (AVB).
You need to entirely.
If you have an (OEM Unlocking enabled) and you intend to run custom software, you can flash a "blank" or "patched" VBMETA that disables verification. samsung error verifying vbmeta image
You wanted to root your phone. You downloaded TWRP (Team Win Recovery Project) and used Odin to flash it. But modern Samsung phones require the vbmeta partition to be patched or disabled when using custom images. If you flash TWRP without also flashing a modified vbmeta (with --disable-verity and --disable-verification flags), the bootloader compares the stock vbmeta signature against the newly flashed recovery. They don’t match. Error triggered. Welcome to the world of — Samsung’s most
To resolve this error, you must either restore the device to its official state or correctly disable the verification flags: You wanted to root your phone
That message in Download Mode is informational. It just means you have a custom binary. As long as your phone boots, no action is needed.