same xpath for two td elements in div - html

Question

i am trying to click on 2nd item(Not Know) in the Td element. I was able to click on the 1st item(known Issue) by using its xpath. How ever i am not able to do the same thing with the 2nd option. i am getting following error
Unable to locate an element with the xpath expression
//*[#id='group_tree']/div/div/div/div[1]/div/div[1]/table/tbody/tr/td[[contains(text(), 'Not Known')]
because of the following error:
below is my code:
driver.findElement(By
.xpath("//*[#id='group_tree']/div/div/div/div[1]/div/div[1]/table/tbody/tr/td[[contains(text(), 'Not Known')]"));
and my HTML is
<div style="display: block;">
<div>
<table cellspacing="0px" cellpadding="0px"
style="background-color: transparent;">
<tbody>
<tr>
<td><img class="tree" src="images/s.gifx" alt=""
style="margin-left: 16px;"></td>
<td class="tree_spacer"><img alt="" src="images/nav_bult.gifx"></td>
<td title="" class="tree_item_text"><a
name="37fd8721a9729140d11a2c59127b17a6">Known issue</a><span></span></td>
</tr>
</tbody>
</table>
<div></div>
</div>
<div>
<table cellspacing="0px" cellpadding="0px"
style="background-color: transparent;">
<tbody>
<tr>
<td><img class="tree" src="images/s.gifx" alt=""
style="margin-left: 16px;"></td>
<td class="tree_spacer"><img alt="" src="images/nav_bult.gifx"></td>
<td title="" class="tree_item_text"><a
name="ea1e8721a9729140d11a2c59127b17fb">Not known</a><span></span></td>
</tr>
</tbody>
</table>
<div></div>
</div>
</div>
i tried finding the element by name, by xpath and contains but everything is throwng error
Please Help

Answer 1

Before doing anything first check if your html is valid, I verified that your html misses matching </img> tags for the existing <img> tags.
Now, I assume you want the td elements with Known issue and Not known as text for a elements.
The following xpaths will give you those :
//td[#class='tree_item_text' and ./a/text()='Known issue']
//td[#class='tree_item_text' and ./a/text()='Not known']