# Mathematica won't maximize my function

I'm trying to maximize two functions. For the first one, the code runs correctly and returns the desired answer

Maximize[{
ax (Log[a] - Log[ax + cy]) +
bx (Log[b] - Log[bx + dy]) +
cy (Log[c] - Log[ax + cy]) +
dy (Log[d] - Log[bx + dy]),
x >= 0, y >= 0, x + y == 1
},
{x, y}]

{ax Log[a] + bx Log[b] + cy Log[c] - ax Log[ax + cy] - cy Log[ax + cy] +
dy Log[d] - bx Log[bx + dy] - dy Log[bx + dy],
{x -> 1/2, y -> 1/2}}


But for the second one,

Maximize[{
(1/2) (x Log[x] + y Log[y] + u Log[u] + v Log[v]) -
(1/2) (x + u) Log[(1/2) (x + u)] -
(1/2) (y + v) Log[(1/2) (y + v)],
x >= 0, y >= 0, u >= 0, v >= 0,
x + y == 1, u + v == 1
},
{x, y, u, v}]


I just get the same thing I wrote as an input

What I'm I doing wrong? How should I fix it?

-

Did you check the answer with NMaximize command?
NMaximize[{(1/2) (x Log[x] + y Log[y] + u Log[u] + v Log[v])

NMaximize::nnum: "The function value Indeterminate is not a number at