CPU spikes randomly

How is it I can be running a project for hours without any CPU issues then comeback an hour later and open the project and it wont play back at all? This happens all the time. I have checked activity monitor and nothing is running that shouldn’t be.

Hi,

Was the computer in sleep/hibernation mode in-between? Could you double-check a system info, if some other application is eating the CPU power?

No we actually had a power cut so it was off.

What I have noticed is that I can have a project with frozen tracks that is working, then I unfreeze some tracks when working on the track and it is still fine, but when I reopen the project I have to freeze the tracks again.

Thinking about it this has been happening for a long time like this.