Saleslogix Web Client Controls are Missing

Every so often we hear that a user can no longer add products to an opportunity whether it is a new opportunity or an existing opportunity. The add product plus sign is missing for no apparent reason.
Why does this happen? What has happened is a deployment was made from a different Application Architect and that install was not updated to match the original Application Architect.
Update the installation of Application Architect to match the original install and redeploy.