i'm using the IWorkbookFormatProvider to open an XLSX, modify some values and save it under another name. Works fine.
Is it also possible to open an XLTX (Excel Template) File with the IWorkbookFormatProvider? That would be the much nicer solution than opening a XLSX and save it under another name. If i just change the source of for the FormatProvider to an .xltx an error is thrown.
Thanx for your help.