iMac logging off for no reason

[Nanabush]

Over the past couple of months my 2011 iMac 21.5", running 10.12.6 has decided to log off after being left without being used after a couple of hours. I have checked the Energy Saver and it is set to computer sleep after about 10 minutes when not in use. I want the computer to remain operating, but in a sleep mode. It logs off instead and it's a pain to re-boot and find the data I have left on screen to work on later. The way I have tried to cure this is by leaving a programme running with its notice asking if I want to save the work. That keeps the computer from logging off. Any suggestions as to where to look to turn off this logging off process?

 

[chscag]

I'm currently running Catalina so I'm going to do this from memory:

Open System Preferences, Security and Privacy. Click on the small lock, enter your password to open it. Now go to advanced.

Check to make sure you do not have a time set to log out after xx minutes of inactivity. Your dialog might be different but you get the idea.

 

[IWT]

Just confirming that the instructions Admin chscag posted are also accurate for macOS Sierra, macOS High Sierra and macOS Mojave - and probably several versions before that.

Ian

 

[Nanabush]

Simple things are sometimes the most difficult. For some reason, I had it set to 45 minutes. It is now unchecked. Thank you for the hint.

Cheers - Ian

 

[chscag]

Glad to hear it's resolved. Sometimes it's the simple things that we forget.