Custom Excel extension returns error when running

Hi,

I created a custom extension to generate Excel files in Thingworx. I basically coded it in Java ( using eclipse by following the extension developer guide ). The extension uses Apache Poi and works fine on my local machine, where excel files are generated with the input data. But after importing the extension to Thingworx, when I run the extension ( through a service ), I get the below error:

Error executing service processExcel. Message :: org/apache/poi/ss/usermodel/Sheet - See Script Error Log for more details.

Nothing else is mentioned in the Script Error Log regarding this error. Since the extension works fine on my local machine and fails when imported into Thingworx, can someone help me by identifying the possible root cause of this error? I tried to google on this issue and it was mentioned to check the Jar files ( check if relevant Poi jar files are added to class path). I checked the JAR files and they seem okay.

Any help soon, will be greatly appreciated.