Rerunning a preflight optimization
If you change the access group's portal, the application, or the application’s skin after running the preflight optimization process, repeat the preflight optimization to remove any unnecessary static content—or add necessary static content—introduced by your changes.
In the header of Dev Studio, click.
On the Preflight Optimization screen, click the Gear icon for the optimized portal.
In the Optimization configuration dialog box, click Submit to repeat the optimization process.