Thanks a lot Newby :-)
Running the newest version (6.2.17) that was based on your patch, I noticed that hitpoints are not getting updated in the ShowEQ client.

Is that because this opcode was not updated? Or some other reason?

Code:
    <opcode id="281f" name="OP_HPUpdate" updated="12/08/22">
        <comment>NpcHpUpdateCode Update HP % of a PC or NPC</comment>
        <payload dir="both" typename="hpNpcUpdateStruct" sizechecktype="match"/>
    </opcode>

Thanks for any help :-)