Installing Open Server 15.5 on top of Open Server 15.0

Open Server version 15.5 is a shelf replacement for version 15.0. When you install Open Server 15.5 into an existing Open Server 15.0 directory, version 15.5 files overwrite the 15.0 files. Sybase recommends that you back up your Open Server 15.0 directory before you install Open Server 15.5.