You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
2Signal: worth watching, 1 to 5
MCPArea: what it touches
ImprovementsKind: in v2.1.242,
ImprovementsSection of the release
What
The single "reserved server name" rejection has been split into three distinct outcomes with separate counts: an internal host server name, an opaque server id, and a malformed manifest.
Details
The error text now states that built-in Claude app servers are never exposed to pages as host servers.
It lists the connectors seen during the session so you can pick a valid server value.
Evidence
internal_host_server_name
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
