Getting Transformer exception while running Jmeter script
<p>While running my JMeter script with 3 threads, ramp-up 5 sec I am getting transformer exception. Actually in my scenario I want to click on the multiple links to the page randomly so I have used the random variable in JMeter But after running, I am getting below error, however, my XPath expression in XPath extractor looks fine.</p>

<pre><code>2016/09/23 23:44:03 INFO  - jmeter.engine.StandardJMeterEngine: Running the test! 
2016/09/23 23:44:03 INFO  - jmeter.samplers.SampleEvent: List of sample_variables: [] 
2016/09/23 23:44:03 INFO  - jmeter.gui.util.JMeterMenuBar: setRunning(true,*local*) 
2016/09/23 23:44:03 INFO  - jmeter.engine.StandardJMeterEngine: Starting ThreadGroup: 1 : Thread Group 
2016/09/23 23:44:03 INFO  - jmeter.engine.StandardJMeterEngine: Starting 3 threads for group Thread Group. 
2016/09/23 23:44:03 INFO  - jmeter.engine.StandardJMeterEngine: Thread will continue on error 
2016/09/23 23:44:03 INFO  - jmeter.threads.ThreadGroup: Starting thread group number 1 threads 3 ramp-up 5 perThread 1666.6666 delayedStart=false 
2016/09/23 23:44:03 INFO  - jmeter.threads.JMeterThread: Thread started: Thread Group 1-1 
2016/09/23 23:44:03 INFO  - jmeter.threads.ThreadGroup: Started thread group number 1 
2016/09/23 23:44:03 INFO  - jmeter.engine.StandardJMeterEngine: All thread groups have been started 
2016/09/23 23:44:05 INFO  - jmeter.threads.JMeterThread: Thread started: Thread Group 1-2 
2016/09/23 23:44:07 INFO  - jmeter.threads.JMeterThread: Thread started: Thread Group 1-3 
2016/09/23 23:44:09 WARN  - jmeter.extractor.XPathExtractor: TransformerException while processing ((//span[@class="title"]/a/@href)[$(RandomNumber)]) Expected ], but found: RandomNumber 
2016/09/23 23:44:10 INFO  - jmeter.threads.JMeterThread: Thread is done: Thread Group 1-1 
2016/09/23 23:44:10 INFO  - jmeter.threads.JMeterThread: Thread finished: Thread Group 1-1 
2016/09/23 23:44:10 WARN  - jmeter.extractor.XPathExtractor: TransformerException while processing ((//span[@class="title"]/a/@href)[$(RandomNumber)]) Expected ], but found: RandomNumber 
2016/09/23 23:44:11 INFO  - jmeter.threads.JMeterThread: Thread is done: Thread Group 1-3 
2016/09/23 23:44:11 INFO  - jmeter.threads.JMeterThread: Thread finished: Thread Group 1-3 
2016/09/23 23:44:11 WARN  - jmeter.extractor.XPathExtractor: TransformerException while processing ((//span[@class="title"]/a/@href)[$(RandomNumber)]) Expected ], but found: RandomNumber 
2016/09/23 23:44:12 INFO  - jmeter.threads.JMeterThread: Thread is done: Thread Group 1-2 
2016/09/23 23:44:12 INFO  - jmeter.threads.JMeterThread: Thread finished: Thread Group 1-2 
2016/09/23 23:44:12 INFO  - jmeter.engine.StandardJMeterEngine: Notifying test listeners of end of test 
2016/09/23 23:44:12 INFO  - jmeter.gui.util.JMeterMenuBar: setRunning(false,*local*)  
</code></pre>