Today Roblox made an update to all games marked as Experimental Mode not be playable by users who are not friends with the creator. This update was made for the safety of all users. Games marked as experimental can still be played by
- The game owner
- Any friends of the game owner
If you no longer have access to a game, that means the game has experimental mode on and you need to befriend the owner in order to play.
When experimental mode is turned on, all clients have the ability to do whatever they want to the game, which is what makes it unsafe. When experimental mode is off, clients can only do what the game developer allows them to do, with a few exceptions. To turn experimental mode off in your game, do the following steps.
- Open your game in Roblox Studio.
- Click on the Game Settings button under the HOME tab.
- Head to the Security tab and turn Experimental Mode off.
DevForum Link: Here.
Questions about the change? Leave them in the comments.