Here’s how to solve the exception: “Can not load 7-zip library or internal COM error! Message: DLL file does not exist.”
Step 1: SetLibraryPath
Add a call to SetLibraryPath before you init SevenZipExtractor.
SevenZipExtractor.SetLibraryPath(@"C:\Program Files\7-Zip\7z.dll"); SevenZipExtractor zip = new SevenZipExtractor(file);zip.ExtractArchive(xsnFolder.FullName);
Step 2: Set Platform Target
Also make sure that your project Platform target is set to Any CPU.