Good morning folks,
I can't wrap my head around this one.
I recently upgraded a failing 250 GB HDD to a 1 TB SSD and transitioned the data using a hard drive duplicator.
When starting from a cold start, the computer boots fine and works very well. However, when starting from a restart, the computer shows the prohibitory sign forcing me to turn off the computer. Since the subsequent start is a cold start, it then works fine again.
Does anyone have any insight as to why a system reboot would cause this behavior?
The OS is Sierra. SDD was checked and repaired using DiskWarrior. Apple Hardware Diagnostics reported "No trouble found"
It may help to note that the original HDD was throwing an I/O error in verbose mode and would not boot, but was able to be copied with a duplicator to the new SSD.