{"version":"2.1.321","anchor":"connector-file-upload-new-refusal-reasons-progress-lines-a","canonical_anchor":"connector-file-upload-new-refusal-reasons-progress-lines-a","heading":"Connector file uploads stream with progress, and blocked-connector messages explain failed checks","tier":"notice","area":"Connectors","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321\/e\/connector-file-upload-new-refusal-reasons-progress-lines-a","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.321","markdown":"### Connector file uploads stream with progress, and blocked-connector messages explain failed checks\n\nFile uploads to MCP connectors stream from disk with progress and new refusal reasons, and blocked-connector notices say when the check itself failed\n\n**What**\n\nMCP connectors are outside services that give Claude extra tools, connected through the Model Context Protocol.\n\nFile transfers:\n\n- Uploads no longer load the whole file into memory. They read it in pieces, check its fingerprint while sending, and stop if the file changes mid-send.\n\n- Uploads report progress, and tool results can carry `connectorFileLines`, a list of files shown in a column under the message.\n\n- New refusal codes: `put_sealed_connector_not_allowed`, `put_tool_policy_not_allowed`, `put_blocked_by_anthropic` and `put_storage_not_connected`. Refusals in the log now carry request IDs.\n\n- Download failure text names a range of offered files, and tool calls with download offers forward progress.\n\n- The cached tool list now expires after a set time rather than by a fixed age check.\n\nBlocked connectors:\n\n- When a plugin's server is blocked and the check against your organization's connector settings itself failed, the message says the server was not connected because the check failed, not that it is turned off. The hint says the plugin's entry for the server may be what the check cannot read. Otherwise it still says an organization admin can change this.\n\n- These notices are tracked separately with a `:check-failed` marker.\n\n- The upload `policy_denied` message is shorter.\n\n**Why**\n\nLarge uploads use less memory, you can see them progress, and refusals say why. If a connector check fails, you are not sent to an admin for a setting that is not the problem.\n\n- Area: Connectors\n- Tier: You'll notice\n- Useful: 2\/5\n- Signal: 1\/5\n- Scope: individual\n- Heads-up: no"}