If you create a new database with KeePass 2.57.1 (at least) one of the default entries "Michael321" has an autotype with (Default) sequence. If you load and then save this database using KeePassJava2 it wont load back into KeePass with the error "Value cannot be null. Parameter name: strSeq"

This is caused by the sequence being empty and the relevant XML element is not serialised. By serializing as an empty element the problem goes away.

Fix in 2.2.5.