Hi Jeff,
I located the log file and am seeing some errors and warnings, but I have no clue what they might mean nor what their impact might be on the problems I've been having.
For example:
10/25/17 09:45:12:193 | [WARN] | | HDSetup | HDPIM | RegisterApplicationCommand | | HDPIM | 75550 | Attempt to register application "/Applications/Adobe Photoshop CC 2018/Adobe Photoshop CC 2018.app/Contents/MacOS/CEPHtmlEngine.app/Contents/frameworks/CEPHtmlEngine Helper EH.app" failed
10/25/17 09:45:12:193 | [WARN] | | HDSetup | HDPIM | InstallHelper | | HDPIM | 75550 | Warning (Code = 186) executing in command 'RegisterApplication' for package: 'AdobePhotoshop19-Core', version:19.0.0.165
10/25/17 09:45:12:199 | [WARN] | | HDSetup | HDPIM | RegisterApplicationCommand | | HDPIM | 75550 | Attempt to register application "/Applications/Adobe Photoshop CC 2018/Adobe Photoshop CC 2018.app/Contents/MacOS/CEPHtmlEngine.app/Contents/frameworks/CEPHtmlEngine Helper NP.app" failed
10/25/17 09:45:12:199 | [WARN] | | HDSetup | HDPIM | InstallHelper | | HDPIM | 75550 | Warning (Code = 186) executing in command 'RegisterApplication' for package: 'AdobePhotoshop19-Core', version:19.0.0.165
10/25/17 09:45:12:365 | [WARN] | | HDSetup | HDPIM | RegisterApplicationCommand | | HDPIM | 75550 | Attempt to register application "/Applications/Adobe Photoshop CC 2018/Adobe Photoshop CC 2018.app/Contents/Required/DynamicLinkMediaServer/dynamiclinkmediaserver.app/Contents/amecommand.app" failed
10/25/17 09:45:12:365 | [WARN] | | HDSetup | HDPIM | InstallHelper | | HDPIM | 75550 | Warning (Code = 186) executing in command 'RegisterApplication' for package: 'AdobePhotoshop19-Core', version:19.0.0.165
Thanks NicoleHickman. Error Code 186 means that the application failed to register. It typically is ignorable although you are also receiving errors when attempting to open Photoshop CC 2018.
As a next step please try opening Photoshop CC 2018 under a newly created local administrator account NicoleHickman. Information on how to set up a new account can be found at Install or run Adobe applications in new user account | Mac OS X .
If Photoshop CC 2018 continues to give you the error posted in message #3 then I would recommend uninstalling and reinstalling in the new account NicoleHickman.
Details regarding the uninstall process can be found at Uninstall or remove Creative Cloud apps . In addition, I would also recommend downloading and running the CC Cleaner tool from Use the Creative Cloud Cleaner Tool to solve installation problems . Once both the uninstallers and CC Cleaner tool are run you can then use the process listed in Learn how to download your Adobe Creative Cloud apps to reinstall Photoshop CC 2018.
Please update this discussion if you have any questions NicoleHickman.