> ## Documentation Index > Fetch the complete documentation index at: https://docs.concord.ad/llms.txt > Use this file to discover all available pages before exploring further. # Limitations and troubleshooting > What the Concord MCP server does not do yet, and what common errors mean. ## Current limitations * **Three tools.** No MCP resources, prompts, or server-initiated notifications. * **One workspace per connection,** chosen at authorization. There is no tool to switch; connect again and pick another workspace on the approval screen. * **Concord cannot ask you a question or request an approval through MCP.** Those turns wait for you in the web app and the call returns `timeout`. See [When Concord needs you](/developers/mcp/ask-concord#when-concord-needs-you). * **Two calls on the same `chatId` at the same time do not queue.** The second attaches to the running turn and returns `answered_previous`; its own message has to be sent again. * **No revocation screen yet.** Approvals cannot be reviewed or revoked from Concord's settings. Contact [support](mailto:support@concord.ad) to revoke a connection. * **Native clients only.** A client that runs entirely inside a web page cannot complete the OAuth flow against Concord today. Desktop apps, CLIs, and server-side agents are fine. * **Protocol revisions.** Concord serves `2026-07-28` and `2025-11-25`. A client that speaks only an older revision cannot connect. ## Troubleshooting | Symptom | Cause | What to do | | --------------------------------------------------------------- | ------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------ | | The client says it is unauthorized and reopens the browser | The token expired, or the connection lost its workspace (you left it, or the approval was reset). | Sign in and approve again. Pick the workspace on the screen if asked. | | "This connection is no longer approved for a Concord workspace" | The workspace pinned to the connection is no longer one you belong to. | Authorize again and choose another workspace. | | "This Concord account cannot act in any workspace" | Your account belongs to no workspace. | Ask a workspace admin to [invite you](/settings/collaborators). | | "This application has been disabled in Concord" | The client was disabled by Concord. | Contact [support](mailto:support@concord.ad). | | Every `askConcord` returns `timeout` on one conversation | Concord is waiting for your approval or an answer. | Open `https://app.concord.ad/chats/`, act, then collect. | | `answered_previous` on a message you meant to send | You sent a message while a turn was still running, usually a retry after a `timeout`. | Collect with `chatId` alone instead of re-sending. Send the message once the turn is done. | | `unknown_chat` | The `chatId` is not an MCP conversation of yours, or is mistyped. | Start a new conversation without `chatId`. | | "Unsupported protocol version" | The client speaks an MCP revision Concord does not serve. | Update the client. Concord serves `2026-07-28` and `2025-11-25`. | | The PUT of an upload is refused | The declared `size` does not match the bytes sent, or the URL expired. | Recompute the size and start again from `prepareUpload`. | Still stuck? Write to [support@concord.ad](mailto:support@concord.ad) with the client you use and, if you have it, the `chatId`. ## Related [Connecting a client](/developers/mcp/connecting) · [Ask Concord](/developers/mcp/ask-concord) · [Uploading files](/developers/mcp/uploading-files)