wpf - TreeView items disappear -

I have a TreeView that is generated in the code, and it will appear in the end:

  & lt; TreeView & gt; & Lt; TreeViewItem header = "X" & gt; & Lt; TreeViewItem header = "Y" & gt; & Lt; TreeViewItem header = "Z" & gt; & Lt; StackPanel Orientation = "Horizontal" & gt; & Lt; Text block width = "100" text = "some text" /> gt; & Lt; Text Box Width = "100" Text = "TextInbox" /> & Lt; / StackPanel & gt; & Lt; StackPanel Orientation = "Horizontal" & gt; & Lt; Text block width = "100" text = "some text" /> gt; & Lt; Text Box Width = "100" Text = "TextInbox" /> & Lt; / StackPanel & gt; & Lt; / TreeViewItem & gt; & Lt; / TreeViewItem & gt; & Lt; / TreeViewItem & gt; & Lt; / TreeView & gt;  

The problem is that when you fully expand this tree and then mark the InStream Tree Whitem (in this case) as "Z", the text block becomes invisible. As long as you do not click on any other item. What am I missing?

Thank you in advance

It looks like you have a theme / skin / style The problem is - the color of the active pictogram is covering the text box

MSDN link:

- A different .xaml theme / skin (for example, the arrow from MSDN ) Try to load.