Clean your Magento 2 Less files. Code Sniffer installer and user friendly Error Viewer.
Add this folder to your Local host and navigate to http://localhost/cleanCode/install Follow the instructions. It will help you to install CodeSniffer and then configure Less Report on Magento 2.
In magento 2.1 If the Error textfile is not generated when you run the batch file Please check the files in following folder are empty in Magento 2.1.
codepool\dev\tests\static\testsuite\Magento\Test\Less_files\blacklist
ee.txt old.txt