When solving systems of linear equations one sometimes gets result like ${0x_n = 0}$ what does it mean for solving the system? Is it error on part of the solver or just feature of the assignment?
Edit: To extend the question. What would such result mean when looking for Nash equilibrium?
What values of $x_n$ satisfy the equation $0x_n=0$?
Answer: all of them. It is just an equation which happens to have infinitely many solutions.
This equation, in other words, does not limit the value of $x_n$ in any way. It doesn't provide a constraint that must be satisfied in the system.