Hi, first try by removing the message header completely. i.e. just have these two tags.
<MessageHeader>
</MessageHeader>
followed by the main body part of the request message.
The web services will work without message header. But it is recommended to always have proper message header so that it will be helpful to debug. As of now, remove it and try. Because if the message header is provided with wrong values, then system will throw error.
Also I couldnt find the AccountingEntryReplicationIn web service in the system. Is it a standard web service? if so, tel me the path to access it?