Steps to Reproduce

Load attached sample file in Keikai

Open it in Excel

Current Result

Excel opens the file

File renders empty in Keikai

Expected Result

File renders in both excel and keikai

Debug Information

caused by importer not recognizing absolute file path in relationships

Excel saves relationship relative to folder

however, the ooxml documentation here shows a relationship using absolute path:

https://learn.microsoft.com/en-us/office/open-xml/structure-of-a-spreadsheetml-document

"/xl/worksheets/sheet.xml"

<?xml version="1.0" encoding="utf-8"?>
    <Relationships xmlns="https://schemas.openxmlformats.org/package/2006/relationships">
        <Relationship Type="https://schemas.openxmlformats.org/officeDocument/2006/relationships/worksheet" Target="/xl/worksheets/sheet.xml" Id="Rddc7711f116045e5" />
    </Relationships>

Workaround

open file in excel and save it.