Thank you for sharing this; we're sorry to hear about it.
What did you try to edit? Did you want to change the background or shape/icon colour? Have you tried to edit your projects with another browser? Have you tried to edit your projects with another browser? What happens if you refresh that page or close it to open a new one after clearing the caches and cookies?
If you want to change the background colour, click it on the project's top left. You will then see the eyedropper tool. If you want to change the colour of an icon or a shape, you click on the element and click on 'Fill' on the left-side panel. You will see the eyedropper tool at the top of the panel. Please be precise about the device, the browser you're using and the OS version. Can you share a screenshot of the files so we can see what you're experiencing?