Sandbox .5 won't open!

[Dilzi]

I just downloaded Sandbox 0.5 after waiting so long today.
But when I open it, it has the BattleField 2 splash screen, the screen goes black then it just cancels back to the desktop.

What's wrong?

[SMILIE]

Have you installed Patch 1.41?

[Dilzi]

Isn't it only 0.5?

[SMILIE]

Battlefield Patch 1.41, not Sandbox