So this is weird - I had an OF update yesterday or so on my MBP 15” running Catalina. I hadn’t seen it come up on my Mac Mini running High Sierra, so I checked and it is running 3.4.6, while the Catalina Mac is running 3.5.
So I manually told the Mac Mini/High Sierra to check for updates, and nothing was found.
So I went to the OF page and downloaded OF 3.5 (latest). The icon has the NOT sign over it. I copied it to ‘Applications and sure enough it won’t launch.
I tried opening from the command line and this is the error I got:
LSOpenURLsWithRole() failed with error -10825 for the file /Applications/OmniFocus.app.
Is OF 3.5 not compatible with High Sierra? I could find nothing that says it.