Thanks. I always run Disk Utility before and after any other utility, be it DiskWarrior, TTP, Carbon Copy Cloner or OnyX – part of my OCD rain dance. In my defense, I've never had a problem. I'm sure that has more to do with OS's since Snow Leopard than my computer skills. 
iMac (19,1, 3.1 GHz i5, 12.7.4, 40 Gb RAM); MacBook Air (1.8 Ghz, 8 Gb RAM, 10.14.6, 256 Gb SSD) Vodafone router and Devolo Wi-Fi Extender, Canon TS8351 printer/scanner.
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