When I tried to add Reference to c# web project by browsing the dll file I got the following error.It is due to missing feature.Net 4.5 framework support.
Only .NET 4.5 supports for zip file manipulation such as adding files, extracting file, etc. you should use third party libraries DotNetZip.
Solution:
I changed .NET 4.0 to 4.5 framework and reference third party library dll.
using (ZipFile zip = new ZipFile())
{
foreach (ListItem item in chkAlbum.Items)
{
if (item.Selected)
{
zip.AddFile(item.Value, "Album");
}
}
zip.Save(Response.OutputStream);
}