1) Browse to the QPS Connect Client application folder and open “QPS Connect Client.exe.config” in a text editor.

2) Update the value of <add name='TraceSwitch' 
value='0' /> from 0 to any number between 1 and 9.

3) Uncomment the section shown below to create a “QPPExceptionLog.log” file at the specified location.

<add name='QPPTextWriterTraceListener' type='System.Diagnostics.TextWriterTraceListener' initializeData='c:\QPPExceptionLog.log' />

4) Uncomment the following section and change TracefileBackupNumber to 25.
<!--<add key ='TraceFile' value ='.\QPS_Log\TraceFile.log'></add>
<add key ='TraceFileSize' value ='1048576'></add>
<add key ='TraceFileBackupNumber' value ='10'></add>

These changes will not result in any performance overhead.
In QPS Connect Client, logging only works at two levels, either at 0 or 1-9.
If you change it to any value other than 0, it will log only minimal data regarding any exceptions