We might be getting could not read file header error when we executing the Jmeter recorded scripts.  This error related to CSV data configured in jmeter scripts.

2015/07/24 15:48:19 ERROR - jmeter.threads.JMeterThread: Test failed! java.lang.IllegalArgumentException: Could not read file header line
 at org.apache.jmeter.services.FileServer.reserveFile(FileServer.java:284)
 at org.apache.jmeter.config.CSVDataSet.iterationStart(CSVDataSet.java:178)
 at org.apache.jmeter.control.GenericController.fireIterationStart(GenericController.java:408)
 at org.apache.jmeter.control.GenericController.fireIterEvents(GenericController.java:400)
 at org.apache.jmeter.control.GenericController.next(GenericController.java:162)
 at org.apache.jmeter.control.GenericController.nextIsAController(GenericController.java:226)
 at org.apache.jmeter.control.GenericController.next(GenericController.java:180)
 at org.apache.jmeter.control.LoopController.next(LoopController.java:123)
 at org.apache.jmeter.threads.AbstractThreadGroup.next(AbstractThreadGroup.java:88)
 at org.apache.jmeter.threads.JMeterThread.run(JMeterThread.java:259)
 at java.lang.Thread.run(Unknown Source)

 Possible Reasons:

1. Make sure that absolute path is provided for CSV file instead of relative path.
2. Before running the jmeter close the file if its already opened.