What's wrong with this entry?
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The MCP authentication flow now supports custom redirectUri parameters and provides better error messages for invalid callback URLs: "Invalid callback URL — no authorization code. The flow is still open; retry with the full redirect URL."
Evidence
OAuth improvements (search for "Invalid callback URL", "No OAuth flow in progress")
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Related
Other releases about the same thing. Found by shared names or similar wording; neither means one caused the other.