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RANGE_MISSING_UNIT

Last updated February 9, 2026

The RANGE_MISSING_UNIT error occurs when the unit identifier of the Range header in a request is missing. The Range header is used to request a specific portion of a resource from the server, and the unit identifier indicates the unit in which the range is specified, such as bytes.

416

RANGE_MISSING_UNIT:

Requested Range Not Satisfiable

AI Assistance

I'm encountering an error and reviewing the docs at https://vercel.com/docs/errors/RANGE_MISSING_UNIT.md to understand what's happening. Please help me resolve this by: 1. **Suggest the fix**: Analyze my codebase context and propose what needs to be changed to resolve this error. If you do not have access to my codebase, ask me for the codebase and try to fix the error based on the information you have. 2. **Explain the root cause**: Break down why this error occurred: - What was the code actually doing vs. what it needed to do? - What conditions triggered this specific error? - What misconception or oversight led to this? 3. **Teach the concept**: Help me understand the underlying principle: - Why does this error exist and what is it protecting me from? - What's the correct mental model for this concept? - How does this fit into the broader framework/language design? 4. **Show warning signs**: Help me recognize this pattern in the future: - What should I look out for that might cause this again? - Are there similar mistakes I might make in related scenarios? - What code smells or patterns indicate this issue? 5. **Discuss alternatives**: Explain if there are different valid approaches and their trade-offs My goal is to fix the immediate issue while building lasting understanding so I can avoid and resolve similar errors independently in the future.

To troubleshoot this error, follow these steps:

  1. Specify unit identifier: Ensure that the Range header in your request specifies a unit identifier like bytes
  2. Check configuration: If the Range header values are being set automatically by some part of your system, check the configuration to ensure the unit identifier is being included
  3. Verify syntax: Verify that the syntax of the Range header is correct and follows the format unit=range-start-range-end, for example, bytes=0-999
  4. Debugging: If the error persists, log the Range header values in your server logs to debug and understand what values are being sent in requests

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