I'm running Node Red on Windows 8. I see some strange things. If I wire up something like this:
it is followed by: "Disconnect from broker:mqtt: //croft.thethingsgirovito.nl:1883"
If I clean my sheet in Node Red (delete all the nodes and deploy again) the connection is restored.
And yes, as pz1 says, Connection fail problems ended there yesterday evening at 22:38:04. After that everything went fine: