ERROR_UNSUPPORTED_COMPRESSION - 618 (0x26A)
The specified compression format is unsupported.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_UNSUPPORTED_COMPRESSION error code indicates that the system encountered a compression format it does not support. This typically occurs when attempting to decompress or compress data using a method that is not recognized by the operating system.
Error Details
- Error Name: ERROR_UNSUPPORTED_COMPRESSION
- Numeric Code: 618 (0x26A)
- Short Description: The specified compression format is unsupported.
This error suggests that the software or application attempted to use a compression algorithm that is not available on the system. Common causes include using an outdated library, attempting to decompress data with a format that has been deprecated, or running into issues with third-party compression tools.
Usage Context
The ERROR_UNSUPPORTED_COMPRESSION error can occur in various scenarios where compression operations are performed, such as file archiving, data transfer protocols, or application-specific data processing. It is important to ensure that the correct and supported compression formats are used for the intended operation.
Developer Interpretation
When encountering this error, developers should verify the following:
- Ensure that the software is using a compatible version of the compression library.
- Check if the specified compression format is supported by the operating system or the application's runtime environment.
- Validate that all required dependencies and updates are installed correctly.
Related Errors
ERROR_INVALID_PARAMETER(87)ERROR_COMPRESSION_FAILED(932)ERROR_NOT_ENOUGH_MEMORY(14)
FAQ
Q: What does the ERROR_UNSUPPORTED_COMPRESSION error mean?
A: It indicates that a compression format not supported by the system was used.
Q: How can I resolve this issue?
A: Verify that you are using a compatible compression library and that all necessary updates are installed. Ensure that the correct compression formats are being used for your operation.
Summary
The ERROR_UNSUPPORTED_COMPRESSION error is a specific indication of an unsupported compression format in Windows systems. Developers should ensure compatibility and correctness when performing compression operations to avoid this error.