Right now many of the domains, including the default home content, use a large amount of textures. Additionally, while it’s in progress, currently we don’t have a good system to limit texture usage so that in a low texture memory situation we degrade the quality gracefully.
If you go into the settings menu and enable the developer menu, and then do into Developer / Render / Maximum Texture Memory and set it to something like 512 or 256, it may allow you to go into domains that use lots of texture memory, although it will reduce the overall quality of the content.
You can also start with an empty domain and start building content that uses either minimal or low resolution textures. Other than that, all you can do is either get a GPU with more texture memory or wait for us to create a new texture pipeline that automatically handles low memory better. It’s on my roadmap and it’s near the top.