Dice don't appear
If you roll and no dice land on the board, check these.
3D dice are turned off on this device
Open your profile and look at 3D dice on desktop and 3D dice on mobile. With them off you don't see the animation, but the result still posts to chat for everyone. The setting is per person and per device.
You don't have a character yet
The dice tray needs a character assigned to you. Before that, Roll does nothing. Type /roll 1d20 in chat instead, or ask your Game Master (GM) to assign you a character.
It was a secret roll
Other players see a secret roll's dice with question marks on them. See Secret rolls.
The dice failed to load
If the 3D dice can't load, for example with graphics acceleration turned off, the tray may show you a total that nobody else sees. Roll with /roll in chat instead, and see The board is slow for the browser settings.