Player cannot see Campaign on their list

Hello, one of my players is unable to see my campaign on his games list. I checked on the campaign, he hasn't been removed as a player. How can we resolve this issue so he can rejoin our campaign? Thank you.

Hello John C., I'm sorry to hear that your player is having issues with accessing your game. To rule out possible issues and provide a baseline for assistance, please have your player carefully work through the following steps of our guide to  Solving Technical Issues : Step 1: Make sure to use the right browser Please check if these issues persist when using both Chrome  and  Firefox. Step 2: Ensure that there are no extensions/addons interfering with Roll20 Please disable  all  add-ons/extensions. Step 3: Clear your cache If none of the above succeeds, please have them thoroughly work through all of the requested information in  Step 4 .  (Don't forget the name of the campaign, player's username, and complete Console Log!) Thank you!