I recently created a sharepoint designer workflow and only site collection administrators could start it. Other users, even those that had full control on a site could not start it and would get an "access denied" message if they tried. To fix it I opened the site in SharePoint designer right clicked on the workflow in the folder list and checked the whole thing out. I then checked the workflow back in and it worked.
用sharepoint designer新建一个工作流，用户无法启动，报错“Access Denied”，只有站点集的owner可以启动工作流。
后来看到上面博客的方法，在designer里将其签出，再签入，恢复正常，具体原因还不知道。