I have Blender 2.78
I have not done anything to my settings besides downloading Archimesh and turned off mipmapping
- I have not updated the plugin
Updating your Blender will automatically add a working filmic. I still don't understand why it isn't working on 2.78. If you lose some of your projects by updating, please understand that you can have more than one Blender on your device.
The current version is 2.79. So it has the Filmic incorporated in it. No need to install it. This question is relevant now.