"NPCHealthMultiplier" server setting not working

[AnHonestSoul]

Normal setting is 1,000000. Changing this to anything else leads to fatal error crash when trying to connect to the server.

Is there any way to make this setting work? Or a mod that has a working NPC health slider?

Would be a nice and easy way to adjust NPC health without having to change every single mob and boss HP one by one in the devkit.