First of all, thanks you for your reply.
I will precise what i am trying to achieve.
I have the exact same issue covered in this topic to which you responded :
https://fenicsproject.discourse.group/t/cannot-open-xdmf-files-in-legacy-version-of-fenics-latest-paraview/10344
My understanding of your last answer is that i have to modify the 5 files as it is presented in this link https://bitbucket.org/fenics-project/dolfin/commits/6fbc9fb8e1272c4cdd73d7e2e432dc29ebfe03ac
That’s why i’m searching those files in order to edit them.
I’m totally new on these topics so please correct me if my understanding is wrong.