GS-Calc appears to be only able to load the older xls format sheets (Excel 2003 and below). Had no luck loading the newer xlsx sheets. Is this correct? The web site clearly states that it can load both.
The xlsx extension in the “Open File” dialog box is used by the “GS-Base” filter (“GS-Base (.xlsx,.xls)”) at this time mainly for exchanging the data in the form of large workbooks with tables with records and e.g. column-based formatting/styles.
If you need individual cell formatting/styles and charts to load/save from/to Excel you should use the OpenDocument *.ods format.
If you have any *.xlsx file that can be open in Excel and you can’t open it in GS-Calc, please contact the support with the information about it’s file size (that is, whether it’s not too big to be emailed) and whether you could email that file.
The xlsx support and related functionality have been changed in the ver. 20. More details:
https://forum-eng.citadel5.com/viewtopic.php?f=7&t=647