Under combo !

Answer me! I did as the tutorial said.

This has happened to me before when I accidentally put a flag on a layer above the ground layer. Are you using layers?

I don't know, I've never touched the layer option though ;P

1) Select the combo from your combo list that you wish to be your undercombo.

2) Data-->Undercombo, and press Okay.

It's really that simple. The undercombo selector tool in the Data menu look for your currently selected combo as what it should set to the undercombo.

The thing about layers is, ... if there's something on layer 0 that you can slash, something that's on layer 1 would be hiding both the resulting undercombo, and the thing that you'd be slashing, so you wouldn't even see the thing to SLASH, much less see the resulting undercombo. 😮dd:

I did excatly as the guide said. How I tried it:
1. I select the tile from right I prefer
2. Data -> Undercombo

It shows:

Under combo

NEW CURRENT
X X

Set Cancel

Set all

3. I press 'Set'. Still stays gray.

that happened to me. i just deleted the screen and redid it and it got fixed

Are you sure the thing you want the under combo to be under actually USES under combos? Some things do not use the under combo, the hammer and lock block combos, for example, use the next combo in the list for what they turn into when activated, not the under combo.

or mabey select "set all"