Using Mozilla FireFox, your initial visit to the Troop 107 Forums will look like this:
Click on the small yellow arrow next to "I Understand the Risks" to expand the text displayed.
Then click on the button labeled "Add Exception".
Click on the button labeled "Confirm Security Exception".
You should then see the Troop 107 Main page or the Forums main page. You'll need to go through this process twice: one time through for the https://forums.t107.org and once for https://www.t107.org
Main Page