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STATUS_MUI_INVALID_LOCALE_NAME
The language identifier in the MUI metadata is invalid
Modern MUI resource configuration uses locale names compatible with Windows language-name rules and BCP 47-style tags, such as en-US. The loader rejects malformed names, unsupported syntax, or values that do not represent a recognized locale for the operation.
The invalid value may be embedded in the resource configuration or inferred from the language-specific directory. This is different from a valid language whose resource file is merely absent.
What to inspect
- Capture the exact locale string, including case, separators, and any script or region subtags.
- Validate the value with Windows locale APIs used by the target operating-system version.
- Compare the embedded language with the folder name containing the .mui file.
- Correct the build or packaging metadata; changing the user display language will not repair an invalid tag.
References
- Microsoft Open Specifications: NTSTATUS values
- Microsoft: preparing a resource configuration file
- Microsoft: user interface language management
- Microsoft: MUI resource management
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