Failed to fetch error when using fetch API in office scripts

The "Failed to fetch" error in Office Scripts occurs when the fetch API fails to make a successful network request. This error is typically encountered when trying to fetch resources from a different domain or when the server returns an error response.

To resolve the "Failed to fetch" error in Office Scripts, you can follow these steps:

1. Check the URL and CORS: Ensure that the URL you are trying to fetch is correct and accessible. If you are fetching resources from a different domain (cross-origin request), the server should have proper Cross-Origin Resource Sharing (CORS) settings to allow requests from your Office Script.

2. Handle Errors: Use try...catch blocks to handle errors gracefully when making fetch requests. This way, you can catch any errors and take appropriate actions, such as logging the error or providing a fallback.

   javascriptCopy code
   try {
     const response = await fetch('https://api.example.com/data');
     if (!response.ok) {
       throw new Error('Network response was not ok');
     }
     const data = await response.json();
     // Handle the data
   } catch (error) {
     console.error('Error fetching data:', error.message);
   }
   

3. Check Connectivity: Ensure that your computer or device has an active internet connection and is not being blocked by any firewalls or network restrictions.

4. Test with Simple URLs: If you are facing issues with a specific URL, try fetching data from a simple URL (e.g., a public API) to see if the error persists. This helps in verifying if the issue is with the server or the network.

5. Test in Different Environments: Test the fetch request in different environments, such as a browser's developer console or a tool like Postman, to isolate any potential issues related to Office Scripts.

6. Check Office Scripts API Requirements: If you are fetching data from a custom API or a service, make sure that the API endpoint is compatible with Office Scripts and adheres to any specific security requirements.

Remember that Office Scripts run within the context of the Office environment, so there might be certain limitations or security settings that you need to consider when making fetch requests.

If the issue persists, you may need to provide more specific information about your code and the API you are trying to fetch data from to receive more targeted assistance.