ERROR_MUI_INVALID_FILE - 15101 (0x3AFD)
The resource loader failed to load MUI file because the file fail to pass validation.
Updated: Feb 21, 2026
Technical Meaning
The ERROR_MUI_INVALID_FILE error code indicates that the resource loader encountered a failure while attempting to load a Multilingual User Interface (MUI) file. This typically occurs when the MUI file does not meet certain validation criteria, preventing its proper loading and use by the system.
Error Details
This error is specific to situations where the resource management subsystem attempts to validate an MUI file before it can be utilized. The validation process ensures that the file contains valid metadata and meets other necessary conditions for correct operation within the Windows environment.
Usage Context
The ERROR_MUI_INVALID_FILE error typically arises in scenarios involving language packs, localized user interfaces, or resource files used by applications to support multiple languages. It can occur during system startup, application initialization, or when attempting to load resources from a specific MUI file.
Developer Interpretation
When encountering this error, developers should understand that the issue lies with the validation of an MUI file. This could be due to incorrect file format, corrupted data, or other issues that prevent the resource loader from successfully loading the required files. Developers should ensure that any MUI files used are correctly formatted and meet all necessary criteria for use within the Windows environment.
Related Errors
ERROR_MUI_FILE_NOT_FOUND(15102): The specified MUI file could not be found.ERROR_MUI_INVALID_SYNTAX(15103): Syntax errors were detected in the MUI file during validation.
FAQ
Q: What does the ERROR_MUI_INVALID_FILE error mean?
A: This error indicates that a Multilingual User Interface (MUI) file failed to pass validation by the resource loader, preventing its use.
Q: How can I resolve this issue?
A: Ensure that any MUI files used are correctly formatted and meet all necessary criteria for use within the Windows environment. Verify that the files are not corrupted and that they contain valid metadata.
Summary
The ERROR_MUI_INVALID_FILE error code is a specific indication of validation failure during the loading process of Multilingual User Interface (MUI) files by the resource loader in the Windows operating system. Developers should ensure that any MUI files used are correctly formatted and meet all necessary criteria to avoid this issue.