A possible reason for this is a crash of TrueLog Explorers internal java engine. When this occurs, the java engine no longer works correctly and will begin to render content which should not be displayed.
When you initially open the TrueLog and browse to the first API node, the rendered text should appear like so:
If you click on the 2nd API node and then return to the 1st API node, the displayed text will have changed to:
The fact that text within the NoScript HTML tag is being rendered indicates the java engine has crashed and it is no longer treating the NoScript tag as expected. Once the internal java engine crashes, the only way to get it working again is to close TrueLog Explorer completely and reload the TrueLog in question.
It's important to note, this is only a rendering issue. It will not impact on the actual load test results because during a load test no client side rendering is carried out. The client requests and server responses will be still performed correctly.
Silk Performer Product Management are aware of the issue and will endeavour to fix it in a future version of Silk Performer.