Simon W. said: Thanks very much for all the replies. To address specific suggestions and how helpful they have turned out to be:- DM Eddie: Thanks, but I can't find the disable chat as option. I've looked in game settings, sheet settings, window settings and page settings, and I'm still unclear where this option is. Kryanic: Thanks, this has solved half the problem! For some legacy reason, my players' sheets have this setting on 'off', whereas the default is 'on. I'm using Roll20 D&D5e sheets. Jarren K: Thanks, but none of suggestions 1-3 are true for my game. So now the residual problem is that one of my players, at least, is able to see the full list of monsters (and imported spell AoE templates) in my game. I note though that when I join the game as a player, I can't see them, nor can an alt account I use for troubleshooting. This player is definitely not set as a GM, but seems to have some of a GM's access privileges(?) I will investigate further. So what I would do is this: work with the player, ask them a name of one of the monsters they see in the drop-down list, and then search in the journal for that monster to find that character. Open up the sheet and make sure that there is nothing in the "Can be Edited and Controlled by" field. If that is blank, and there are no other monsters with the same name, then that sounds like some kind of bug. My next step would be to kick the player from the game and then reinvite them to see if that would 'refresh' which sheets they are controlling.