If you got the same or similar error, it is related to the YUICompressor, which was mentioned. It would be great to go to the repo of the YUICompressor (https://github.com/yui/yuicompressor/issues) and create or vote for similar tickets there. Thx. Plugin to minify JS , CSS and HTML for quicker page load times by reducing the size of js/css/html files. This plugin remove all unnecessary characters from source code, without changing its functionality. These unnecessary characters usually include white space characters, new line characters, comments, and sometimes block delimiters, which are used to add readability to the code but are not required for it to execute.