使用Apache POI加载xlsx文件时出现NullpointerException

Am tryng to read a file using Apache POI 3.8 in mac osx environment, which is created in Windows using Open XML SDK 2.0 for Microsoft Office, am getting null pointer exception as it is unable to load the xlsx file. Below is the stack trace. I am able to open the file and view it.Am tryng to read a file using Apache POI 3.8 in