In CodeMix 2019.6.11, we started using indentation settings from Eclipse to indent your code with tabs, or a fixed number of spaces. Prior to this release, indentation settings for CodeMix editors were separate from those of other Eclipse editors. If your Eclipse and CodeMix settings did not match, you will now be indenting your code with tabs instead of spaces, or vice versa, resulting in linting tools picking these up as warnings as you edit your code.