ERROR:An error occurred in SoapUI log when I run my Load Test

Tue Apr 11 15:46:00 EDT 2017:ERROR:An error occurred [Invalid index:1000, size=1000], see error log for details

Why I am getting this error message in my SoapUI log ? Please note, I started getting this error message after I added a Groovy script I found on the forum here to write "SoapUI log" to a text file.

//Clean up previous log
//com.eviware.soapui.SoapUI.logMonitor.getLogArea("SoapUI log").clear()
//def LogFile = new File("C:\\dump\\soapUI-Logs-to-file.txt")
//log.info "Clearing previous logs..."
//LogFile.delete()

//The below groovy script step is to capture the soapUI log area.
// "soapUI log" can be replaced with http log, jetty log, script log, error log etc based on the need.
def logArea = com.eviware.soapui.SoapUI.logMonitor.getLogArea( "SoapUI log" );
def logFile = new File("C:\\dump\\soapUI-Logs-to-file.txt")
//This is the first line in the soapUI log file.
logFile.write("soapUI Logs In a file.\r\n")
if( logArea !=null )
{
def model = logArea.model
if( model.size > 0 )
for( c in 0..(model.size-1) )
logFile.append(model.getElementAt(c).toString() + "\r\n")

}

UPDATE

I played with the test suite options with no luck :( 

I played with the load test options with no luck :(