I was able to solve by hand 1st order differential equation which Mathematica could not solve. Is there some kind of award for such an achievement? :)
ClearAll[y, x, f]
DSolve[y[x]^2 + f[x]*(-1 + x*y[x]) + y'[x] == 0, y[x], x]
10.4.1 can't solve it. It is Riccati first order non-linear but can be solved analytically fairly easily actually (else I would not have been able to do it !