What does Windows error code 14100 (ERROR_XML_ENCODING_MISMATCH) mean?

ERROR_XML_ENCODING_MISMATCH

The character encoding in the XML declaration did not match the encoding used in the document.

ERROR_XML_ENCODING_MISMATCH is Windows status 14100 (0x00003714) associated with an XML document whose declaration disagrees with the actual byte encoding.

Likely impact: Different parsers may decode the mismatch differently, so accepting it can make package behavior nondeterministic.

Typical causes

• the file declares UTF-8 but contains UTF-16 bytes.
• a BOM conflicts with the declaration.
• text was transcoded without updating the declaration.
• a tool writes locale bytes into a fixed declaration.

Troubleshooting steps

1. Verify that the XML declaration, byte-order mark, transport metadata, and decoded bytes identify the same encoding.
2. Collect raw leading bytes and BOM and XML declaration.
3. Compare the byte-order mark, XML declaration, and raw bytes of the failing file, then identify the producer or transcode step that introduced the disagreement.

Useful evidence

• Collect producer and transcode step.
• Collect parser line and byte offset.

Recovery and retry

Regenerate the XML from one authoritative Unicode representation with matching declaration and bytes; do not patch only the displayed text.

Related errors

ERROR_XML_PARSE_ERROR is a general syntax failure; this code specifically identifies encoding disagreement

Example

A servicing manifest declares UTF-8 but was saved as UTF-16LE. Re-exporting it with matching declaration and bytes allows parsing.

References

• Microsoft: exact Win32 system error range
• Microsoft: Assembly manifests
• Microsoft: Side-by-side assemblies