Evaluating a third party data processing tool, I have bumped into a case where some WinZip files cause an exception: Caused by: gnu.java.util.zip.ZipException: Unknown compression method 98 at gnu.java.util.zip.ZipFile.getInputStream(ZipFile.java:470) I have seen this with files created with WinZip 11.2 and newer. What's the latest version of WinZip (or compatible compression method) that the zip.dll can handle? I've been hunting for some reference on this, but other than unversioned source code, I have had little luck so far.