The coffee machine was switched on when the milk valve was removed. The door was then closed.
Close and open the door.
Insert the holder without the stainless steel bolt and silicone seal until it audibly engages.
If the holder is unable to engage, close the door again and reopen it until the holder is able to engage.
When the holder engages, close the door and wait until initialisation is complete.
The drinks menu is displayed.
Then reinsert the entire milk valve as follows.
Open the door and remove the holder.
Insert the stainless steel bolt from above.
Insert the silicone seal into the milk valve holder.
Insert the holder and silicone seal until they audibly click into place.