Free Memory doesn't work

[Marqin]

Prometheus version: 1.4.1
node_exporter version: 0.13
Grafana version: 4.0.2

Error Screenshot:

Error name: Multiple Series Error

Error stacktrace:

.execute/i</h.prototype.setValues@http://127.0.0.1:3000/public/app/boot.85c49108.js:20:17161
.execute/i</h.prototype.onDataReceived@http://127.0.0.1:3000/public/app/boot.85c49108.js:20:15993
e.prototype.emit@http://127.0.0.1:3000/public/app/boot.85c49108.js:48:17521
.execute/d</a.prototype.emit@http://127.0.0.1:3000/public/app/boot.85c49108.js:48:19604
.execute/i</f.prototype.handleQueryResult@http://127.0.0.1:3000/public/app/boot.85c49108.js:42:19793
g@http://127.0.0.1:3000/public/app/boot.85c49108.js:38:29545
h/<@http://127.0.0.1:3000/public/app/boot.85c49108.js:38:29717
xc/this.$get</o.prototype.$eval@http://127.0.0.1:3000/public/app/boot.85c49108.js:39:5353
xc/this.$get</o.prototype.$digest@http://127.0.0.1:3000/public/app/boot.85c49108.js:39:3835
xc/this.$get</o.prototype.$apply@http://127.0.0.1:3000/public/app/boot.85c49108.js:39:5638
x/i<@http://127.0.0.1:3000/public/app/boot.85c49108.js:39:1804
f@http://127.0.0.1:3000/public/app/boot.85c49108.js:37:15602
jb/k.defer/c<@http://127.0.0.1:3000/public/app/boot.85c49108.js:37:17066

[Marqin]

I've tested it both with version on grafana.net and with github version.