Error: The data could not be loaded completely because the maximum number of columns per sheet was exceeded.

I am using version (x64) Windows 10 core 64390860c6cd0aca4beafafcfd84613dd9dfb63a
I can load this excel spreadsheet on other versions of Excel, Windows 7, 8 10. Just not using this LibreOffice version.
This document has 17 sheets, no sheet more than 30 columns, no sheet more than 50 lines. no sheet with a cell containing a large data figure. Do not understand why this darn version will not load this simple document. I am ready to dump this version of Excel.

Astur, How do I attach a excel data file.

I found how to add an attachment.
Also, I believe I solved the problem. Apparently the individual that built this spreadsheet setup each sheet by setting up each sheet by removing all of the lines, thus excel thinks all cells in each sheet used. I am experimenting by cleaning up the file on an old excel version, then see if it will load on Libre.

If a sheet is protected then all cells might be counted for number of columns.

You might try to unprotect sheet in excel or try Google sheets which I think can manage the same number of columns.

There is the possibility to increase the number of columns available in LibreOffice 7 but it might not end well as it’s an experimental feature

It might also be that all columns of a sheet are formatted to something, e.g. number format, colours, borders, … which results in excess columns marked as “used”.

If there’s no data missing you can regard the message as just a warning and continue.