iMac booting from external SSD hangs at startup

[Mike Boreham]

My friend Mister George who is more than 80 years old bought the cheapest solution because he has no much money. But is USB 3.0 not compatible with APFS?

For most purposes booting from an SSD USB 3 is fine..... APFS compatible.

 

[Mac Hammer Fan]

The external SSD is a Crucial 256 GB and the problems appeared after upgrading to Mojave APFS.