Unable to connect with distant computer

Hi!

I am computer A with linux using v 13.2.13582

I try to connect with computer B and the answer ( in french ) is: 

Teanviewer n'est pas en cours d'exécution sur l'ordinateur de votre partenaire (B)

I can connect with computer C ( another computer )

Computer B can connect with me (computer A) with no problem. 

I don't know why A cannot connect with B.  Do you have an idea? Thank you

mylapk