Due to the version of Apache POI currently used in KNIME AP, there are some issues related to reading and writing older format Excel files. We are actively working on a fix, but I don’t have an ETA for that.
In the meantime, as a workaround, you might open the problem file in Excel and save it in XLSX format. Sorry for the inconvenience!
I see it’s been a while since any comments have been made here however I am experiencing this exact issue and have not found a fix yet. I’ve tried the nightly builds and that has not worked. I am still unable to open old Excel files. I still get this error:
Execute failed: The supplied spreadsheet seems to be Excel 5.0/7.0 (BIFF5) format. POI only supports BIFF8 format (from Excel versions 97/2000/XP/2003)
I am attempting to use the XLS reader. Is there another tool I can use instead? Or is there a fix for this in the works still?