FYI - This appears to still be an issue in version 7.3.4.2 when opening both .xls, .xlsx, and .ods formats created in earlier versions. Using sample files with only one sheet and with only meaningful data in the first approx. 50 rows and approx. 15 columns, the error still shows up. I could not find any conditional formatting or other non-default formatting in other non-data cells, so I’m not sure where else I could look to try to help troubleshoot.
I hope this is helpful.