Commented Unassigned: Excel Import / Export [4703]

Excel Import / Export seems to have been changed
I can't import Excel-Files created with older Versions anymore.
Excel Worksheet-Layout differs.
Comments: ** Comment from web user: ep90 **

I got it working, but:
I can get only the "Singe sheet" Export working, and this works for Import with both, single and multiple sheet excel files.
But if I select "Multiple sheets" non of them works, I get the attached error message even if i do an export, immediately followed by an import.

Since the "Singe sheet" method works, its not a severe issue to me now.

Thanks