Many of you are joining Project Spark over a year and a half since the servers closed down, and have been disappointed because of lag issues. Although I do not know why, since the servers have come down, Project Spark has a problem on Xbox One where it stops and starts every 2-3 seconds. This is easily solved.
Yes, it can be fixed. And it is an easy fix.
When you get to the main menu where it says Play Create and you see the animation is not fluid and is stopping and starting: Press your Xbox button, Select Project Spark game, Press the ≡ button and select Quit. Relaunch Project Spark.
The game will load again, and this time it will be okay. You will have to do this for 90% of all Project Spark sessions.
If you are getting lag problems in anything you create after this, then you may have to look at improving your koding, as it is likely to be a fault in the programming causing the lag. Beware of creating 30 items per second because you forgot to add a [once] tag. However, there are also limitations to how many character brains you can run at any one time without lag issues, and with reduced memory capacity as you fill up your Xbox with your creations, you may not be able to create battlescenes (for example.)
You may also run out of space. You will get a warning telling you that you may not be able to save. If this happens you will need to start deleting some of your saved levels. I recommend hunting down the saves of unnamed levels which are unlikely to be something you want to keep. If you have levels with lots of little experiments or designs in, then consider putting them all into one level and deleting the rest.
Interestingly, despite the multiplayer and community server access been unavailable your levels are still saved to the cloud as well as your local machine (I know this because I have 2 Xbox’s and while I create on one, it synchronises to the other so they have identical saved levels). But you cannot save the level on one Xbox and delete it on another, it will synchronise and remove on both.