<requirements compare_type="or">
<requirement name="HoldingItemHasTags" tags="perkSalvageOperations"/>
<requirement name="HoldingItemHasTags" tags="perkTheHuntsman"/>
<requirement name="HoldingItemHasTags" tags="perkDeepCuts"/>
<requirement name="HoldingItemHasTags" tags="perkPummelPete"/>
<requirement name="HoldingItemHasTags" tags="perkElectrocutioner"/>
<requirement name="HoldingItemHasTags" tags="perkJavelinMaster"/>
<requirement name="HoldingItemHasTags" tags="perkSkullCrusher"/>
<requirement name="HoldingItemHasTags" tags="perkBrawler"/>
<requirement name="HoldingItemHasTags" tags="perkGunslinger"/>
<requirement name="HoldingItemHasTags" tags="perkBoomstick"/>
<requirement name="HoldingItemHasTags" tags="perkDeadEye"/>
<requirement name="HoldingItemHasTags" tags="perkMachineGunner"/>
<requirement name="HoldingItemHasTags" tags="perkArchery"/>
<requirement name="HoldingItemHasTags" tags="perkTurrets"/>
</requirements>
<passive_effect name="HeadShotOnly" operation="base_set" value="1">
<requirement name="EntityTagCompare" target="other" tags="zombie"/>
<requirement name="IsLocalPlayer"/>
</passive_effect>
</effect_group>
You can try that. Replace the code in entityclasses.
But eh. Servers annoy me. I generally don't bug fix for servers.