The upgrade code will automatically create a new page template, error_default. This will be used to display error pages. The new tags <txp:error_status /> and <txp:error_message />, when placed in the template, will include the error code (“404 Not Found”) and message respectively.

If a template matching the error code is found (“error_404”, etc), that will be used as the template. error_default is used when no matching template exists. If error_default is missing, or if the database is unavailable for some reason, a hard-coded page will be used as a last chance fallback.

The code is in the 4.0 development branch, and will be included in the next release (4.0.2).