# AI clients & API (https://sellersheetai.com/help/troubleshooting/ai) > Every refusal says what went wrong and what to do. Here is each one, and its fix. Every refusal carries a sentence in `notification.message` — your agent reads it to you — and, when only you can fix it, a note in `human_action`. The HTTP status says which kind it is ([Responses & errors](/docs/mcp-api/responses)). ## Signing in [#signing-in] | Symptom | What it means | Fix | | ------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------- | | "Unauthorized" (401) | Your sign-in or key is missing, expired, turned off or deleted — or it's the wrong kind (an MCP key on the Tool API, or the other way round) | Sign in again in your client, or create a new key under **Settings → API & MCP** | | The browser never opens | The client is older than MCP sign-in | Update the client, or use an [API key](/docs/mcp-api/keys) | | Sign-in says you've reached your keys | Each browser sign-in creates an MCP key, and your plan's keys are all in use | Delete an unused key under **Settings → API & MCP**, or upgrade | | 403 for a key that used to work | You are no longer an active member of the workspace the key belongs to | Ask the workspace owner, or use a key of your own | ## Stores [#stores] | Symptom | What it means | Fix | | -------------------------------------- | ----------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | Store ref refused (400) | The ref has no marketplace, like a bare `myStore` | Pass a ref with its marketplace, like . The error lists every ref that works — or take one from `get_user_context` ([Store refs](/docs/mcp-api/store-refs)) | | "Store is paused" (403) | None of its marketplaces is active on your plan | Upgrade, or free a slot under **My Stores → Edit Marketplaces** (in the app: **Settings → Stores & Marketplaces → Edit markets**) | | "No stores" | No store is connected yet, or none is shared with you | [Connect your store](/docs/start/connect) | | Ad tools come back empty | Ads was never authorized for that store | **Ads** on the store's row in **Settings → Stores & Marketplaces** | | The store shows an authorization error | Amazon's authorization was revoked or expired | **Reauthorize on Amazon** on the store's row | ## Permissions [#permissions] | Symptom | What it means | Fix | | ------------------------------------- | ----------------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------- | | 403 on a write tool | The key or your membership has read access on that store | Use a key with write access on it, or ask the workspace owner for it ([Stay in control](/docs/mcp-api/control)) | | 403 on a store you can see in the app | The key is **Restricted** and that store isn't on its list, or its reach is one workspace | Add the store to the key, or use another key | ## Limits and Amazon [#limits-and-amazon] | Symptom | What it means | Fix | | ------------------------ | --------------------------------------------------------------- | ------------------------------------------------------------------------------------------------ | | 429 with `Retry-After` | A plan window is full, or Amazon's own quota for that operation | Wait the seconds `Retry-After` says, then retry ([Credits & limits](/help/app/settings/billing)) | | 402 | Not enough Credits for an image, copy or insights action | Top up on **Settings → Billing & Credits** — nothing was charged | | 400 with Amazon's errors | Amazon refused the request — a wrong attribute, a missing field | Read `errors`: it is Amazon's own list; fix the input and send again | | 503 | Amazon, noon or SellerSheet could not answer just then | Retry after `Retry-After` | | A call times out | Some Amazon reports take a minute or two | Raise your client's MCP tool timeout; on the Tool API, run long workflows over MCP instead | ## Sheets [#sheets] | Symptom | Fix | | ------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------- | | Your agent can't write to your sheet | Open Google Sheets → **Extensions → SellerSheet → Open Sidebar** once to set up the workspace | | A file "isn't yours" | Drive and sheet tools work only on files you own or that are shared with you, inside your workspace — share the file with your Google account | Still stuck? Write to [support@sellersheetai.com](mailto:support@sellersheetai.com) with the time of the call.