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.
if (__DEV__) {
          if (inst.state === null || inst.state === undefined) {
            const componentName = getComponentName(Component) || 'Unknown';
            if (!didWarnAboutUninitializedState[componentName]) {
              warning(
                false,
                '%s: Did not properly initialize state during construction. ' +
                  'Expected state to be an object, but it was %s.',
                componentName,
                inst.state === null ? 'null' : 'undefined',
              );
              didWarnAboutUninitializedState[componentName] = true;
            }
          }
        }
        partialState = Component.getDerivedStateFromProps.call(
          null,
          element.props,
          inst.state,
        );
        if (__DEV__) {
          if (partialState === undefined) {
            const componentName = getComponentName(Component) || 'Unknown';
            if (!didWarnAboutUndefinedDerivedState[componentName]) {
              warning(
                false,
                '%s.getDerivedStateFromProps(): A valid state object (or null) must be returned. ' +
                  'You have returned undefined.',
                componentName,
              );