1st check here for php error – delete the file and re run the request
c:\Temp\PHP70x64_errors.log
2nd Check for YII errors
c:\anisiis\test.cartzlink.com\httpdocs\admin\protected\runtime\application.log
How to Debug CRM Errors
c:\Temp\PHP70x64_errors.log
c:\anisiis\test.cartzlink.com\httpdocs\admin\protected\runtime\application.log