The Auto-Detect option, according to AMD Moderator Matt, is temporarily removed which is why you are getting that error.
Here is the Second generation Vega driver for the Radeon VII GPU card: https://www.amd.com/en/support/graphics/amd-radeon-2nd-generation-vega/amd-radeon-2nd-generation-veg...
I believe you clicked on the wrong driver to download.