Answered Furthest upgrade from 2.0.7

If you still have the 2.3.2 version installed, try disabling all plugins by right-clicking on them in the tree. If that fixes things, re-enable them one at a time until things break. You could also try updating all snippets and plugins and manually deleting all files in the core/cache directory.

That's quite a big jump (your version was released in January of 2011). You might have to upgrade to some of the intermediate versions, but you should be able to go to 2.3.3 eventually. I'd try this sequence: 2.1.0, 2.2.0, 2.2.10, 2.2.16, 2.3.2 -- testing as you go. I'd also suggest disabling all plugins before you start, you may have a plugin that's incompatible with later versions. Turning off the compress_css and compress_js System Settings is also a good idea. Some users uninstall and remove extras, especially neglected or exotic ones, and reinstall them in Package Manager after MODX is current.

Many extras have been updated for later versions of MODX because of compatibility issues, but you won't see them in Package Manager until after you upgrade to later versions of MODX.

The intermediate versions of MODX are available here:

http://modx.com/download/previous-releases/

If you run into trouble, try manually deleting all files in the core/cache directory and clearing your browser cache and cookies (or going incognito). Be sure all users are logged out when you upgrade.

Upgrading those sites is critical because the older versions have some serious security vulnerabilities.

In answer to your original question, lots of people have upgraded from 2.0 to 2.3, but most of them did it gradually.

[2015-03-11 22:09:49] (ERROR @ {Install Directory}/core/model/modx/modscript.class.php : 47) PHP warning: Creating default object from empty value

Can you tell us what was in the chunk that caused trouble?