Native code supports threads... To support this efficiently... the system blocks the thread and then unblocks it when something interesting happens. Interesting. Thanks for that. Taking a step back, if you poste a copy of your sample I’d be happy to take a look. Use the text attachment feature (the paperclip icon) to avoid clogging up the timeline. Thanks for that. I tested some samples the other day after reading your notes. I got as far as getting an inkling, so your offer is very much appreciated. Sample 1 of 3 - https://developer.apple.com/forums/content/attachment/f7fa2e80-33b1-48e4-b552-cdb8b030d4f0 Sample 2 of 3 - https://developer.apple.com/forums/content/attachment/af1565bc-aaff-4916-a60e-981c0d1c8d35 Sample 3 of 3 - https://developer.apple.com/forums/content/attachment/c40115c6-2d02-42a7-93fc-bb9b2e128d9d

Developer  My Mac Name  Automatically Show Web Inspector for JSContexts This nailed it. Brilliant. But actually all the other stuff you ended up explaining is really interesting and helpful. It'll take some time to get a handle on it, but very much appreciate all your help. SOLVED. Thank you!

The changes have to be saved after implementation... tell application "Contacts" set countPeopleBefore to count of people repeat while (count of people) is greater than 0 set thisPerson to person 1 delete thisPerson end repeat set countPeopleAfter to count of people save (* This line makes the difference *) end tell