Wrong matrix import
Use the file attached to https://bugs.kde.org/show_bug.cgi?id=455977. The first line of the file is used for the header There shouldn't be any header shown in the preview and the proper number or rows has to be imported.
Use the file attached to https://bugs.kde.org/show_bug.cgi?id=455977. The first line of the file is used for the header There shouldn't be any header shown in the preview and the proper number or rows has to be imported.