I encountered the issue "To create nodes of type 'ELEMENT, a valid name must be specified".
I was importing from a Tab-Delimited (.txt) file that had been saved from an Excel file (.xlsx). The source Excel file had additional columns, even though they were empty, with no column headers, no data, apparently they still ended up in the tab-delimited file.
The solution for me was to delete the additional columns in Excel and re-save the file as tab-delimited. After that the import worked perfectly.
Thanks,
Ken