My troubleshooting technique:
Problems: 1. Adobe CS5.5 performance in High Sierra. 2. After installing a wireless mouse and USB wi-fi plug, my two CD drawers would open on cold boot.
Solution: "Google it". Somebody somewhere has had the problem and knows how to fix it.
More problematic was when my internet connection failed (new supplier) and the only way to contact the supplier was by, um, internet. The solution was to wait for three hours. I spend far too much time on the internet. I hardly knew what to do with myself...
iMac (19,1, 3.1 GHz i5, 10.14.6, 40 Gb RAM) with Mac Pro (5,1, dual-2.4 GHz, 10.13.6, 24 Gb RAM) used as a server and to run 32-bit apps via Screen Sharing. MacBook Air (1.8 Ghz, 8 Gb RAM, 10.14.6, 256 Gb SSD) all patched through a Vodafone 4-port Home Hub and BT Wi-Fi Extender.