Conversion of xlb files to xlsx file format

Even though both .xlb and .xlsx files originate from Microsoft Excel, it is not very likely that one can be converted between another, because of their different type. XLB format is used to sabe toolbars, which are GUI elements that can be added/changed in Excel and .xlsx is the standard excel table, meaning xlb to xlsx conversion is certainly not possible.

Open XLB file    Open XLSX file