SigmaZone Support

Support – File Format or Extension Not Valid

File format or File Extension is not Valid While the “file format or file extension is not valid” error is typical, some users have also reported the error “QuantumXLAddIn.xlam is not a valid add-in” which has the same root cause and workaround.  Root Cause – Windows Defender security setting and misleading error reporting When Attack Surface […]

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