This might be a reference to this one: https://github.com/facebook/react/issues/10212#issuecomment-346302374

The problem still exist.

So, trying to render with server side and got this error. I don't have this notation in my code but this might be a problem with dependencies.

```
TypeError: Cannot read property 'toLowerCase' of undefined
    at ReactDOMServerRenderer.renderDOM (/Users/lukasborawski/Dev/web-client/node_modules/react-dom/cjs/react-dom-server.node.development.js:2304:27)
...
```

```
"react": "^16.1.1",
"react-dom": "^16.2.0",
```

Thx for help.
expectTextNode(e.childNodes[2], ' ');
          expectTextNode(e.childNodes[4], ' ');
        } else {
          expect(e.childNodes.length).toBe(3);
          expectTextNode(e.childNodes[0], ' ');
          expectTextNode(e.childNodes[1], ' ');
          expectTextNode(e.childNodes[2], ' ');
        }
      });
      itRenders('a div with text sibling to a node', async render => {
        const e = await render(
          <div>
            Text<span>More Text</span>
          </div>,
        );
        let spanNode;
        expect(e.childNodes.length).toBe(2);
        spanNode = e.childNodes[1];
        expectTextNode(e.childNodes[0], 'Text');
        expect(spanNode.tagName).toBe('SPAN');
        expect(spanNode.childNodes.length).toBe(1);
        expectNode(spanNode.firstChild, TEXT_NODE_TYPE, 'More Text');
      });
      itRenders('a non-standard element with text', async render => {