How to Solve Below Error

These errors while dealing with excel, word, etc. files processing are often deceptive.

 

Most probably you don't have office installed on the production server where you are hosting it hence you get error. It works on dev pc because you have office installed.

 

try installing office interop assemblies, read here

https://docs.microsoft.com/en-us/visualstudio/vsto/how-to-install-office-primary-interop-assemblies