Should you keep the engine updated or stick with one version?

So when making a game do you recommend to keep the engine up to date at all times or should one keep the version the project has started with because updating might cause issues with an old engine version project?

Or is it easy to migrate an old project onto a newer, up to date engine version without trouble?

Thoughts?

Unless an update to the engine has something you absolutely need then it’s best to stick with one version–basically, “If it ain’t broke, don’t fix it”
Updating can potentially make things stop working so you want to avoid it if you can.

Just backup your project before you try and update it.

It also depends a bit on how early in the project you are. Early on I’m more inclined to update to get more features to work with. In the later stages the risk is higher compared to the reward.