On the map list that map shows a little quill on the map which means it's been altered. Right click with the mouse on the list and click on the Revert icon (2 curved arrows twisted around each other).
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I'm not sure what is going on here at all. The quill icon indicates that Unity is finding the correct file and is trying to add the LoS layer onto the map. When you open the map it should default to LoS on, so if the icon isn't selected then something is stopping that process. I have checked every map in ToA and the LoS is on all of them. Also I did this one ages ago and if there was an issue I'm sure that I would have had a number of reports but it's only you that seems to have the issue. If you've re-downloaded the module then it points to something in your client but then I would think you would see this issue in other modules as well. The only thing I can suggest is that you delete the two rulesets 5e.pak and CoreRPG.pak files from your rulesets folder and do another update. If that doesn't work then try deleting the fantasygrounds.exe file from the installation folder and then update FG from the updater in the same location. One other possibility is that an extension you are using is the problem but since you've tried in a new campaign that's unlikely - unless you also enabled the same extensions as in your main campaign. But just to be sure try in a new campaign with nothing - not even a theme selected (if you haven't already).
Did you try it in a clean/new campaign?
I started working on Rise of the Drow. I imagine it'll take 2-3 weeks to finish, but wanted to give anyone who was wondering about it a heads up...