How to create a .xlsx file in C#. I am using Microsoft.ACE.OLEDB.12.0. On my local machine it is working fine. When I deploy the same code to server, its not working. Microsoft.ACE.OLEDB.12.0 is not registered on the server. Issue is not to install anything on the server. Please let me know how to fix the below attached code, creating .xlsx file without installing any exe on the server. I can include .dll with the the code that fix this issue?