Had a tricky problem which took a little while to solve today: Some users were granted contribute permissions to a SharePoint site, but only members of the Owner group could see the site – everyone else got this message.
At first I thought it might have been a problem caused by the migration of this site from QA to Production (which only happened a few days before) – but the site looked fine. Then I noticed that some of the services were shut down on the server (including the “server” service, which was causing problems with the Search index distribution as having it off prevents SMB shares from being created or used) – but the problem remained when the services were re-enabled.
Then I started thinking through all of the situations where something like this error would appear and it occurred to me that someone might have changed the permissions on the siteassets library or something similar… so to test I went to a document library (which I knew did not have security access based on a page library) and saw the same error there as well! But… I could get to a list with one of the problem accounts, no worries.
It turned out that one of the administrators (who has since received some more training) decided to lock down access to the Document library… but was a bit overzealous and also locked down access to the “Site Pages” library in the same site! That explained why half the pages were coming up access denied for the majority of users. And because the inheritance had been broken on the Doc Library, the SharePoint groups had to be added there as well. Essentially the root cause was User Error caused by a Poor Governance model and lack of training.
So what’s the moral of the story? If you have access permissions for some users but not all, the solution may be as simple as checking the security of the lists and libraries that appear on this page: http://MyFancySite/_layouts/uniqperm.aspx – you are looking for unique permissions on Site page libraries.