How to unlock all stages in Melee in dolphin 5.0?

I enabled all the characters and stages using a gecko code. It gave me the characters, but not all of the stages.

Solution 1:

In Dolphin 5.0-14344, to unlock all stages in the USA or PAL versions of Super Smash Bros. Melee:

1. Open Options > Configuration.
2. In the General tab, check Enable Cheats.
3. Right-click Super Smash Bros. Melee in the gamelist and select Properties.
4. In the Gecko Codes tab, check Unlock All Characters and Stages.
5. Launch Super Smash Bros. Melee.

To answer your question specifically, I tested the "Unlock All Characters and Stages" Gecko Code in Dolphin 5.0-14344 on 4 different versions of Melee: USA 1.00, USA 1.01, USA 1.02, and PAL with empty save files and confirmed all stages were unlocked as expected. It's possible an older version of 5.0 may have had a bug preventing the cheat from working.