In SharePoint 2010, you may experience this message on your page that you are trying to edit/view:
Important StatusStatus: This page has been declared a record or placed on hold and is locked as read-only
1. Ensure that no other users have checked-in the page. You may have to ensure that the page has been Checked-out for you to to edit the page.
2. Ensure you have the appropriate permissions to edit the page.