Premiere Pro CC 2018: "...install seems to be damaged..."
uninstall everything cc including preferences, https://helpx.adobe.com/creative-cloud/help/uninstall-remove-app.html
then uninstall the cc desktop app, https://helpx.adobe.com/creative-cloud/help/uninstall-creative-cloud-desktop-app.html
clean your computer of cc files per http://www.adobe.com/support/contact/cscleanertool.html
restart your computer (don't skip this)
reinstall the cc desktop app, https://creative.adobe.com/products/creative-cloud.
I am running Sierra 10.12.6 on an older Mac Pro (Late 2013):
Model Name: Mac Pro
Model Identifier: MacPro6,1
Processor Name: 6-Core Intel Xeon E5
Processor Speed: 3.5 GHz
Number of Processors: 1
Total Number of Cores: 6
L2 Cache (per Core): 256 KB
L3 Cache: 12 MB
Memory: 16 GB
Boot ROM Version: MP61.0116.B46
SMC Version (system): 2.20f18
Illumination Version: 1.4a6
Any ideas for things I haven't done yet?