Learn To Resolve Error Exception From Hresult 0x800a03ec Issue.

Hello all,
While coding in C#, I want to open a workbook in MS Excel, but it shows an error exception from hresult 0x800a03ec. On debugging, I found out that the error is due to the following code:
AppXls.Workbooks.Open(Textbook1.text, , , , “mypass”);
Here, AppXls is the Dim object.
Here is the screenshot of the error

