<p dir="auto">I referred create-react-app sample and added more pages, but everytime I click on router link, I throws below error</p>
<blockquote>
<p dir="auto">Warning: Material-UI: You can only instantiate one class name generator on the client side.<br>
If you do otherwise, you take the risk to have conflicting class names in production.</p>
</blockquote>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have searched the <a href="https://github.com/callemall/material-ui/issues">issues</a> of this repository and believe that this is not a duplicate.</li>
</ul>
<h2 dir="auto">Expected Behavior</h2>
<p dir="auto">I should not be getting the above warning</p>
<h2 dir="auto">Current Behavior</h2>
<p dir="auto">Everytime you click on route link it throws warning</p>
<h2 dir="auto">Steps to Reproduce (for bugs)</h2>
<p dir="auto"><a href="https://codesandbox.io/s/6z2jn1xyrw" rel="nofollow">https://codesandbox.io/s/6z2jn1xyrw</a></p>
<h2 dir="auto">Your Environment</h2>
<p dir="auto">See codesandbox.io link for more details</p>
<table role="table">
<thead>
<tr>
<th>Tech</th>
<th>Version</th>
</tr>
</thead>
<tbody>
<tr>
<td>Material-UI</td>
<td>v1.0.0-beta.12</td>
</tr>
<tr>
<td>React</td>
<td>16</td>
</tr>
</tbody>
</table>
<p dir="auto">Fresh problem with last beta 26 in Select component. See steps for reproduce.</p>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have searched the <a href="https://github.com/mui-org/material-ui/issues">issues</a> of this repository and believe that this is not a duplicate.</li>
</ul>
<h2 dir="auto">Expected Behavior</h2>
<p dir="auto">On blur event the label MUST be moved above the field.</p>
<h2 dir="auto">Current Behavior</h2>
<p dir="auto">On blur event the label return back to select field and mixed w/ selected items context</p>
<p dir="auto"><strong>onFocus</strong><br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/814184/34521305-2355ac12-f09e-11e7-949c-f3a460cc2f54.png"><img src="https://user-images.githubusercontent.com/814184/34521305-2355ac12-f09e-11e7-949c-f3a460cc2f54.png" alt="image" style="max-width: 100%;"></a></p>
<p dir="auto"><strong>onBlur</strong><br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/814184/34521315-2d049480-f09e-11e7-86cd-cd7fbdb8ad78.png"><img src="https://user-images.githubusercontent.com/814184/34521315-2d049480-f09e-11e7-86cd-cd7fbdb8ad78.png" alt="image" style="max-width: 100%;"></a></p>
<p dir="auto">Absolutely the same problem on your demo site <a href="https://material-ui.com/demos/selects/#multiple-select" rel="nofollow">https://material-ui.com/demos/selects/#multiple-select</a></p>
<h2 dir="auto">Steps to Reproduce (for bugs)</h2>

<ol dir="auto">
<li>Going to <a href="https://material-ui.com/demos/selects/#multiple-select" rel="nofollow">https://material-ui.com/demos/selects/#multiple-select</a></li>
<li>Select some items in multiple select example</li>
<li>Click on any space on page</li>
<li>See how label mixed with selected variants on field</li>
</ol>
<p dir="auto"><a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/814184/34524270-ec20258e-f0ab-11e7-82c2-8e800fb5515c.png"><img src="https://user-images.githubusercontent.com/814184/34524270-ec20258e-f0ab-11e7-82c2-8e800fb5515c.png" alt="image" style="max-width: 100%;"></a></p>
<h2 dir="auto">Context</h2>

<h2 dir="auto">Your Environment</h2>

<table role="table">
<thead>
<tr>
<th>Tech</th>
<th>Version</th>
</tr>
</thead>
<tbody>
<tr>
<td>Material-UI</td>
<td>1.0.0-beta.26</td>
</tr>
<tr>
<td>React</td>
<td>15.6.2</td>
</tr>
<tr>
<td>browser</td>
<td>Chrome 63.0.3239.84 for Mac</td>
</tr>
</tbody>
</table>