If you’re one of the brave people who’ve installed Apple’s new Mojave (macOS 10.14) operating system, you may be experiencing extreme sluggishness and steady slowdowns after boot until everything just freezes up and you can’t do anything. It’s really exasperating, but there’s a cure for the freeze-ups… If your Mac’s primary drive has multiple partitions, and/or you have an external drive attached, and/or your external drive has multiple partitions.
FLASH: Updated 10/25/18 with NEW INSIGHTS on how to deal with the prohibitory symbol. When installing the macOS Mojave 10.14 beta 11 and then the public macOS Mojave 10.14, I ran into the prohibitory symbol again, actually twice during both installations, but got through to the final install in both cases. You should read this entire article, but if you’re in a hurry, jump to the section covering working around hitting the prohibitory symbol twice.
TOP NEW TIPS
- If you get the prohibitory symbol multiple times, you may have to shut down and restart your Mac multiple times.
- Boot into another APFS-based partition, like High Sierra (macOS 10.13), run Disk Utility, and then run First Aid on the Mojave partition. If Disk Utility reports that it fixed the Mojave partition — or even if it just gave the partition a clean bill of health — I’ll bet your problems will be solved.