--- updatedAt: 2025-09-04T18:39:52.000Z agentTools: projectIndex: https://developer.clickup.com/llms.txt --- # Common Errors Common errors you may encounter while using the ClickUp API. # Common errors Unsuccesful requests will return an HTTP status code other than `200`. They'll include a JSON error message and error code. ## Common errors ### XMLHttpRequest from origin has been blocked by CORS policy This error is displayed when you make requests directly from a local environment or frontend application, such as Javascript Axios or Fetch. You can create a proxy script using any server-side language and then use Javascript to send requests. ### Rate limit reached `HTTP status code 429` The API is [rate limited](https://developer.clickup.com/docs/rate-limits) per OAuth and personal token.\ You'll receive a `429 HTTP status code` response if you exceed the rate limit. ### Team not authorized `OAUTH_023`, `OAUTH_026`, `OAUTH_027`, and `OAUTH_029` to `OAUTH_045` This error is thrown when a team (Workspace) was not authorized by the user for a particular access token. ### Token not found `OAUTH_019`, `OAUTH_021`, `OAUTH_025`, `OAUTH_077` This error is thrown if authorization is [revoked by the user](https://developer.clickup.com/docs/authentication#personal-token). ### Authorization Header Required `OAUTH_017` The authorization token was missing in the **Authorization** header of the request. ### Client Not Found `OAUTH_010` The client application was not created correctly. #### Error code ### Redirect URI not passed `OAUTH_017` The redirect URI was not present during the [OAuth authentication flow](https://developer.clickup.com/docs/authentication#oauth-flow). ### Redirect URI does not match the redirect uris of this application `OAUTH_007` The [redirect URI](https://developer.clickup.com/docs/authentication#oauth-flow) must be registered with your client application. ### Webhook configuration already exists `OAUTH_171` A webhook has already been created using this configuration and location.