What
When managed settings stop a plugin from a skills directory loading, the message names the two policies responsible, strictKnownMarketplaces and blockedMarketplaces, so you know what to ask an administrator to adjust.
Evidence
strictKnownMarketplaces or blockedMarketplaces
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Names in the bundlestrictKnownMarketplacesblockedMarketplaces
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Confirmed since
Anthropic's documentation has since written up blockedMarketplaces, on Create and distribute a plugin marketplace.
A [marketplace hosted on claude.ai](/docs/en/discover-plugins#add-from-claude-ai) is matched by host: a `hostPattern` entry that matches `claude.ai` governs it, in `strictKnownMarketplaces` and in `blockedMarketplaces`. On the allowlist, s…plugin-marketplaces see the edit
Confirmed since
Anthropic's documentation has since written up strictKnownMarketplaces, on All settings.
| Restriction allowlists | Takes the list whole from the highest source that sets it, without adding entries from lower sources. When the highest source doesn't set one, takes it whole from the next source down | [`availableModels`](#avail…settings-reference see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up strictKnownMarketplaces, on All settings.