Milk System Cleaning

[Tani]

I have a Jura S8 machine. When cleaning the milk system the machine used to pump in the cleaning water solution and rinse the system. Today I found out that the machine is not sucking the rinsing solution, and only steam is coming out of the frothing nozzle. Has anyone owning the Jura S8 experienced this problem, and how did you fix that? Thank you in advance for help.