install ezflow_clean using setup wizard
login in admin
publish and article
The error will appear once you click "Send for publishing" button

{"error_text":"","content":{"unvalidated-attributes":[],"stored-attributes":{"217":217,"218":218,"219":219,"220":220,"221":221,"222":222,"223":223,"224":224,"225":225,"226":226,"227":227,"228":228},"valid":true,"message_success":"Draft saved at 11:43 am","message_ago":"(0 minutes ago)","timestamp":1363862591,"preview":"<div class=\"preview-header\">\n    <h1 class=\"context-title\">\n        <a href=\"#\" class=\"close\">&laquo;&nbsp;Back to the edit form<\/a>\n        <img class=\"transparent-png-icon\" src=\"\/share\/icons\/crystal-admin\/32x32\/mimetypes\/document.png\" width=\"32\" height=\"32\" alt=\"\" title=\"\" \/>\n        Preview of &lt;New articleasdf&gt; in siteaccess\n        <select class=\"no-autosave\">\n                    <option value=\"ezflow_site\" selected=\"selected\">ezflow_site<\/option>\n                    <option value=\"eng\">eng<\/option>\n                    <option value=\"ezflow_site_admin\">ezflow_site_admin<\/option>\n                    <option value=\"iphone\">iphone<\/option>\n                <\/select>\n        <img src=\"\/extension\/ezautosave\/design\/standard\/images\/as-loader.gif\" alt=\"Loading...\" style=\"display:none\" id=\"iframe-loader\" \/>\n    <\/h1>\n    <div class=\"context-information\">\n        <p class=\"left preview-warning\">\n            <strong>Warning:<\/strong> <em>following links from the preview will take you to the live version of the website<\/em>\n        <\/p>\n        <p class=\"right translation\">\n            English (United Kingdom)&nbsp;<img src=\"\/share\/icons\/flags\/eng-GB.gif\" width=\"18\" height=\"12\" style=\"vertical-align: middle;\" alt=\"eng-GB\" \/>\n        <\/p>\n        <div class=\"break\"><\/div>\n    <\/div>\n<\/div>\n<iframe src=\"\/ezflow_site_admin\/content\/versionview\/59\/1\/eng-GB\/site_access\/ezflow_site\"><\/iframe>\n"}}