{
	"icons": {
		"48": "landmarks-w48.png",
		"96": "landmarks-w96.png"
	},

	"browser_action": {
		"default_title": "Landmarks",
		"default_icon": {
			"18": "landmarks-w18.png",
			"32": "landmarks-w32.png",
			"36": "landmarks-w36.png",
			"64": "landmarks-w64.png"
		},
		"default_popup": "popup.html"
	},

	"applications": {
		"gecko": {
			"id": "ariaLandmarkNav@ibm.com",
			"strict_min_version": "45.0"
		}
	}
}

{
	"icons": {
		"48": "landmarks-w48.png",
		"96": "landmarks-w96.png"
	},

	"browser_action": {
		"default_title": "Landmarks",
		"default_icon": {
			"18": "landmarks-w18.png",
			"32": "landmarks-w32.png",
			"36": "landmarks-w36.png",
			"64": "landmarks-w64.png"
		},
		"default_popup": "popup.html"
	},

	"applications": {
		"gecko": {
			"id": "ariaLandmarkNav@ibm.com",
			"strict_min_version": "48.0"
		}
	}
}

Use correct minimum Firefox version
Use correct minimum Firefox version
