title: Ole::Storage::FormatError: OLE2 signature is invalid
body: <p>I want to read an Excel File in my Rails Application. </p>
  
  <p>This is how I open my Excel file and read it.</p>
  
  <pre><code>doc = Spreadsheet.open('./try.xls', "r")
  sheet = doc.worksheet 0
  sheet.each do |row|
  array_rows &lt;&lt; row.to_a
  end
  </code></pre>
  
  <p>I have it as a rake task.When I try to Read this file it throws an error.</p>
  
  <pre><code>Ole::Storage::FormatError: OLE2 signature is invalid
  </code></pre>
  
  <p>What is happening? what should I do?</p>