The code is build without error and the statement in question is
SevenZipExtractor zip = new SevenZipExtractor(file_name);
The error is
Unhandled exception of type 'SevenZip.SevenZipLibraryException' occurred in SevenZipSharp.dll
Additional information: Can not load 7-zip library of internal COM error!
Message: DLL file does not exist.
I've also installed and downloaded from 7-zip.org.