6.0.0&Problem with Git Push

Hello,

I have followed the tutorial for insert and use Git in my project.
I have created a local repository where I use to work and a cloned version on a shared folder with other collegues.
When I commit to my local repository, everything works fine. When I push to the “shared” branch, I get the following error:

Anyone knows how to solve the problem?

Thanks since now,
Daniele