Hi,
Is it correct that you observe the "File is locked for editing by another user" in some environments, but this error is not reproducible in other environments?
The general description of this error and a few possible causes can be found in the following article:
In addition, could you please check whether the presence of this error is related to the installed Microsoft Excel version?
Also, does the order in which the same workbook is opened by Microsoft Excel application and JExcel affect the observed behavior?
For example, is the same error present if you open the workbook in Microsoft Excel first and then open it using JExcel?