The type of `ySplit` in the `pane` is set as `row_t`, but it should be some fractional type. This causes the following error. terminate called after throwing an instance of 'xml::parsing' what(): xl/worksheets/sheet2.xml:2:656: error: invalid value '1.0' https://docs.microsoft.com/en-us/previous-versions/office/developer/office-2010/cc880269(v%3Doffice.14) https://github.com/tfussell/xlnt/blob/master/source/detail/serialization/xlsx_consumer.cpp#L515 This document was generated by exporting from Google Docs.