One of my players cannot see his token.

Hi, I have been assigning tokens to my four players. Three of the players can see their tokens and these have a blue dot on the right hand side of the token. One player cannot see his token, no matter how many times I amend/update/delete and start again the token. This one has a mauve (or pink) dot on the right side of it. I suspect, I am missing an obvious step here, but some assistance would be appreciated. Thanks!

Make sure that you've given the player permission to edit his own sheet, that you've set up his token, assigned it vision and then attached it to the sheet as the default token.