Please help ! A problem suddenly arose last week

You can write your topic however you want, but you need to answer these questions:

  1. What do you want to achieve? Keep it simple and clear!
    Originally, the game involved boarding and controlling the rocket transport vehicle when the game starts. Currently, the rocket transport vehicle does not appear when the game begins.

  2. What is the issue? Include screenshots / videos if possible!
    The rocket transport vehicle is visible in the studio,
    but it disappears when the game starts.

  3. What solutions have you tried so far? Did you look for solutions on the Developer Hub?
    I looked for a solution, but I couldn’t find one.

Please let me know how to resolve this issue. Thank you.

  1. You shouldn’t be directly referencing in the workspace. Instances load to the client after they join, so they won’t be available immediately. Use WaitForChild to wait for these instances to load.
  2. By default, games have streaming enabled, meaning physical models and parts will load and unload dynamically as the player moves around depending on their distance, device, and connectivity. This means that if a player is too far away or have a weaker device at a weaker graphical settings, the model may not exist.
  3. If you need models to persist even if the player is far away, ensure your parts are grouped in a model and set it’s ModelStreamingBehavior to Persistent and wait for it to initially load using WaitForChild. Any descendants in that model will also be present at it loads atomically, meaning complete. This should really only be used for any important game mechanics that require some models to be loaded at all times, such as teleporters, camera parts, etc. Overusing this behavior defeats the purpose of streaming.
  4. Otherwise, you can use CollectionService by tagging your models and listening to it via CollectionService:GetTagged(), CollectionService:GetInstanceAddedSignal(), CollectionService:GetInstanceRemovedSignal(). You can read more on everything here: Instance Streaming | Documentation - Roblox Creator Hub