# BODY_NOT_A_STRING_FROM_FUNCTION

The `BODY_NOT_A_STRING_FROM_FUNCTION` error occurs when a function returns a body that is not a string. It's essential that functions return a string body to ensure that they can be correctly processed and executed.

## Troubleshoot

To troubleshoot this error, follow these steps:

1. **Check function return type:** Ensure that the function is structured to return a string. If the function is returning a different data type, modify the function to return a string, using `JSON.stringify()` if necessary
2. **Review function code:** Inspect the function code for any logic that might cause a non-string value to be returned
3. **Check data types:** If the function is processing input data or retrieving data from external sources, ensure that the data is being correctly converted to a string before being returned
4. **Review function logs:** Check the [function logs](/docs/runtime-logs#type) for any errors or warnings that might indicate why a non-string value is being returned


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title: "DEPLOYMENT_BLOCKED"
description: "The deployment was blocked due to certain conditions. This is a deployment error."
last_updated: "2026-02-03T02:58:41.666Z"
source: "https://vercel.com/docs/errors/DEPLOYMENT_BLOCKED"
--------------------------------------------------------------------------------