I am facing one issue like "External table is not in the expected format." with 2013 micro enable excel . when i am trying to open the connection string for reading the excel file i.e oleConn.Open(); . Can any one help out, how to fix the issue. I have tried all possible ways to fix it. Same connection string used in multiple pages in the application and all other place working fine except one page. This is asp.net application and c# coding.