Last night I received an issue wherein a site collection admin was getting the below error only on the home page of her site. We tried with all WFEs and even with a test user account but could not replicate the issue.
How I resolved it: -
Since she was a site collection admin, it was safe to give her full control anywhere. The home page was a publishing page that uses masterpages and page layouts. So I went to the master page gallery and provided her full control and bingo it worked ! Next day she again received the same error. One of our team member went into the checked out files section and took ownership of all her files. And shoot, this time he was able to replicate the issue. we did a simple Binary search and were able to find out the culprit file and took it our of the library. Next thing, client regained her access. :)