Symptoms
After you install the December 2022 or January 2023 security updates for SharePoint Server, you might not be able to browse to a SharePoint website if the site URL ends in a string that matches a blocked file type extension for that web application. When you browse to such a site, you might receive the following error message:
The URL '/sitename' is invalid. It may refer to a nonexistent file or folder, or refer to a valid file or folder that is not in the current Web.
Resolution
To fix this issue, install the following security update, as appropriate:
