When a Windows Update client connects to an internal server that has custom content published to it, the client may encounter error code 0x80240fff. After encountering this error, the client can no longer install updates.
This error can occur if custom content uses a Product name that matches an existing Category name. For example, this can occur if you create a product within SCUP named "Tools". This leads to an issue when evaluating the categories since there is now a product named "Tools" and an update classification called "Tools".
In order to resolve this issue, you must find the custom content that uses a Product name matching an existing Category name, and decline or modify that custom content. The problem will be corrected when there are no longer any custom updates with a Product name that matches an existing Category name.
In environments using multiple WSUS servers, you must make sure that the problematic custom content has been declined or modified on all servers in the hierarchy.
for other considerations.