Kettle 6.1 and XLSX File

Hi to all guys,
i need your help to understand a strange situation.
I need to import some data from an xlsx file that containt 16 sheet.

Actually the xlsx file has a dimension of 20MB.

If i try to import it as Apache POI Kettle crash... i've already tried to increase JVM options in spoon.bat but i don't have a large amount of memory in the server.

For this reason io try to import the file using Apache POI Streaming and it works like a charm.

For the previous operation i was using a test file.

When my import job was ready, i receive the real file, and the job runs correctly without importing a single row.

I've see that the only difference between the test file and the real file is this:
Test file: program name: microsoft excel
Real file: program name: apache poi


so it seems that id the xlsx file is created with Apache POI kettle is not able to read its content.

Any ideas?

Thanks in advance