User name replaced with ,#,#,#,#

Question

Over the fall, we upgraded our sharepoint 2007 site to sharepoint 2010. We only updated the platform and back end though, we left it set up with the same 2007 sharepoint look and feel. Once we upgraded, we started to come across several problems, one of
the more annoying ones is users with all but full admin permissions to sites getting locked out of pages they have access to and edit capabilities to. Sharepoint allows the user to edit a page but when they try to check it in, their username is replaced with
",#,#,#,#" and then they get denied access because no user named ",#,#,#,#" has access to our site. Has anyone else experienced this problem or has a suggestion of where to start looking
to solve it? It happens on every page

Answer 1

Hi,
Let’s verify the following:
Make sure that all the Master page, CSS files, any other files that are required are published. If there are files that are required in the master pages and are not published, users will get access denied even if they have full control on the site.
Provide global read access to the master page library. Site actions > site settings > Master Page and page layouts > Library tab > Permissions. Add All authenticated users to READ ONLY. 
Here is a similar post, refer to it:
http://sharepoint.stackexchange.com/questions/60699/user-with-full-control-permission-is-getting-access-denied-message
whether the issue persists in any other site collection within the same web application. Add a new "User Policy" for the web application that allows "All Authenticated Users" the permissions "Full Read" on the desired zone.
http://underthehood.ironworks.com/2011/05/sharepoint-2010-access-denied-for-users-that-have-full-control-on-the-site.html
http://technet.microsoft.com/en-us/library/ff758656.aspx
Best Regards,
Lisa Chen
Lisa Chen
TechNet Community Support