Windows desktop repair utility · v2.1.1 · 2026-08-27
Excel says the file format or extension is not valid
The error may indicate corruption, a wrong extension, encryption or a file that is not actually an Excel OOXML document.
✓ XLSX / XLSM✓ DOCX / DOCM✓ Local repair✓ Windows 10/11
Document diagnostics
OOXML / ZIP integrityOK
XML structureOK
RelationshipsCHECK
Excel / Word internalsREPAIR
Visible progress and current repair stage.