iMac 27" - 2017 - system update problem

[udflyer]

Looking for tips.

Whenever I do a system update (like to 10.14.5) today, I usually have to physically hold the power on/off button once during the process.

Almost like usually the 1st or 2nd system reboot shuts the iMac down but does not reboot it to carry on the update.

After I hold the button down a while it starts up and the update proceeds with no issues.

I have tried disconnecting all peripherals, no help.

No big deal other than annoying and curious if anyone else has the issue ?

 

[mikehalloran]

Without knowing anything about your system, what 3rd party apps you may have installed, if there are external drives or partitions, if you have another copy of the Mac OS installed on anything connected or many other variables, no one is going to know.

You can try resetting the NV RAM and doing a Safe Boot.

If a chronic problem, Console.app will tell you but you may have to engage a knowledgeable tech to help out.