This usually happens on devices with a new security patch. The tool V2.0 may not support devices updated to the very latest Android security patches (e.g., August 2023 onwards). You may need to look for a newer version of the tool (V3.0 or higher) or use the official Vivo unlock method.
: Tools to fix bootloops caused by corrupted system files. Download Unlock Bootloader Vivo Fix Tool V2.0