I've upgrade to High Sierra. Dreamweaver launched initially, but now it fails just before opening fully. The 'adobe 11.0 All update' won't run so I'm stuck! I've updated all the Java but that didn't help either?
The old Creative Suite Installers are not supported by Sierra. See the terminal workaround described below.
Keep in mind that Legacy CS5 is not certified to run on High Sierra. Since CS5 is no longer sold or supported, you use it at your own risk.
The other option is to revert to an older OS that can support CS5. Or get a virtual machine or 2nd computer for your legacy software needs.