I want to solve an equation. By Mathematica, it take a long time. What the problem?

Can anybody help me?

The code is as follows:

```
b = FullSimplify((4 g Sqrt(
n (1 + n)) (-1 + 2 g Sqrt((Eta))) Sqrt((Eta)) (1 +
g (1 + 2 Sqrt(n (1 + n))) (-1 + g Sqrt((Eta))) Sqrt((Eta)) +
2 n (1 - g Sqrt((Eta)) + g^2 (Eta))) (Kappa) ((Kappa) -
2 g Sqrt((Eta)) (Kappa)) - (1 -
2 g Sqrt((Eta))) (2 Sqrt(n (1 + n)) +
g (1 + 2 n + 2 Sqrt(n (1 + n))) (-1 +
g Sqrt((Eta))) Sqrt((Eta))) ((1 - 4 g Sqrt((Eta)) +
8 g^2 (Eta)) (Kappa)^2 + ((CapitalDelta) + (CapitalOmega))^2)))
Solve(b == 0, n)
```