When building a checklist you need to make sure you are using categories to break it up.
As you are building the checklist, minimize the categories as you complete them.
You can open and close categories with that little red arrow on the far right of the black category bar.
This is what an open category looks like:
Each question that is displayed on the screen has a significant amount of data that it has to relay to you. If you have a lot of these open, the browser has to render them and keep them in current memory.
As you finish categories, minimize them to free up resources as you continue to develop.
**Make sure you save often so that you don't lose any of the changes you have been working on