We've encountered a problem using the XTeaEncryptionFileAdapter under .NET with Db4objects.Db4o.dll Version 6.3.500.0. There is a problem with configuring db4o to use Xtea. It throws a TypeLoadException, saying, that the method Open() is not implemented. A quick look at the source code of XTEA has shown, that the Open() method is not correctly implemented for that version of db4o. One parameter is missing: bool readOnly.