Be sure to manually install the folder called "police_overhaul_wfire" into your dlcpacks folder in openIV.

Here is the path in your mods folder to the place you need to drag and drop it:

mods - update - x64 - dlcpacks

Then add this line: <Item>dlcpacks:/police_overhaul_wfire/</Item> to you dlclist.xml located here:

mods - update - update.rpf - common - data