There is a markdown issue in step Install MySQL in locale: en. Error: Markdown contained an unclosed tag: ["code"] For `mapping values are not allowed in this context` errors, the reported line number may be misleading (due to https://github.com/ruby/psych/issues/190). Check any YAML (eg. in your `---code---` blocks) as missing colons, or a missing space after a colon, are common issues. Try pasting the YAML into this linter if you're stuck: http://www.yamllint.com/