If the milk carafe is not frothing the milk, there can be various causes and solutions.
1. The milk carafe parts are dirty.
• Detach all parts and clean them with warm water /washing-up liquid.
2. The milk carafe dispensing spout is not completely pulled out.
• Check that it is fully pulled out.
3. The milk tube is not well connected to the frothing element.
• Attach the milk tube properly to the frothing element.