illegal character error when using AddFile

Oct 21, 2011 at 7:30 PM

I'm getting an illegal character error message when using the following code:

ZipFile apizip = new ZipFile(zipfilename);
                    apizip.CompressionLevel = Ionic.Zlib.CompressionLevel.BestCompression;
                    apizip.Encryption = EncryptionAlgorithm.WinZipAes256;
                    apizip.Password = "********";

string barcodemgmtbin = apiroot + "\\barcodemanagement\\barcodemanagement\\bin\\release\\";

apizip.AddFile(barcodemgmtbin + "com.kwiktag.api.barcodemanagement.dll", "KTPrivateAPI\bin");

apizip.Save();
The full value of the filename on my development machine is C:\\!KT\\KwikTag\\trunk\\source\\server\\api\\barcodemanagement\\barcodemanagement\\bin\\release\\com.kwiktag.api.barcodemanagement.dll
Any ideas on what I'm doing wrong?