1. How are you checking the character's vision? Are you using Ctrl-L as DM, or DM logged in as a player, or using a Dummy character? 2. Are you using Legacy Dynamic Lighting or Updated Dynamic Lighting? Have you checked the settings for both of them (not just the one you are intending to use)? 3. What happens if you turn on Global Illumination and/or Daylight mode? 4. Are the tokens set to "represent" a character that the viewing player can control? Are the players able to move the token? Make sure you move a token - sometimes the vision doesn't update until the token is moved. 5. What happens if you turn off Fog of War, Advanced Fog of War, Dynamic Lighting, and Explorer Mode? (Try each of these individually until the tokens are able to see something.)