# Possible errors and solutions

This documentation provides a reference for common API errors encountered when calling BoldSign APIs, including their causes, solutions, and key fields to verify for troubleshooting.

## Common API Errors and Solutions

### 400 - Bad Request
**Cause:** This error occurs when the request payload contains invalid data, the JSON is malformed, or required fields are missing.

**Solution:**

- Ensure that the request body follows the correct format.
- Check for any missing or misspelled required fields.
- Validate that all data types are correct.


### 401 - Unauthorized
**Cause:** This error occurs when there is a mismatch between the user’s registered data center and the API endpoint, or when the API key or OAuth token is invalid or expired.

**Solution:**

- Ensure API requests are sent to the correct data center endpoint.
- Verify that the API key is valid and not expired.
- Check if the OAuth token has expired and renew it if necessary.

For a detailed guide on resolving this issue, refer to our [Knowledge Base Article](https://support.boldsign.com/kb/article/14423/resolving-401-unauthorized-error).

### 402 - Payment Required
**Cause:** This error occurs when the user’s account has payment issues, such as an expired subscription or insufficient balance.

**Solution:**

- Verify that the account has an active subscription.
- Ensure that the payment method is valid and up to date.

### 403 - Forbidden
**Cause:** This error occurs when the user does not have permission to access the requested resource.

**Solution:**

- Check the user’s role and access levels to confirm the necessary privileges.


### 404 - Not Found
**Cause:** This error occurs when the requested API endpoint is incorrect or the resource does not exist.

**Solution:**

- Ensure that the URL is correct and properly formatted.
- Verify that the resource exists before making the request.

### 417 - Exception Failed
**Cause:** This error occurs when the request body contains invalid or improperly formatted data.

**Solution:**

- Ensure that all fields in the request body contain valid data.
- Validate input values before sending the request.

### 422 - Unprocessable Entity
**Cause:** This error occurs when the request payload is correctly formatted but contains invalid data.

**Solution:**

- Check that all fields meet validation requirements, such as correct email formats and valid numbers.
- Ensure that all required fields are populated with appropriate values.

### 500 - Internal Server Error
**Cause:** This error occurs due to an unexpected issue on the server side.

**Solution:**

- Retry the request after some time.
- If the issue persists, check the server logs or contact [support](https://support.boldsign.com/support/tickets/create) for further assistance.