Method not found: 'Void EasyXLS.ExcelDocument..ctor(Int32)'.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.MissingMethodException: Method not found: 'Void EasyXLS.ExcelDocument..ctor(Int32)'.

I'm getting this error when I publish from my development machine to the server.

On the developer machine I have installed EasyXLS Trial for .NET v6.1. And on the server I have installed Express Writer for .NET - Server Edition v6.1.exe.

Using the Express Writer version you can create a spreadsheet having only one sheet from a dataset or a list.
The constructor ExcelDocument(int worksheetCount) is useless. You can use the constructor that doesn't have parameters, ExcelDocument(). You will get the same spreadsheet result.