Macbook pro applcations keep freezing
The apps on my 2018 Macbook Pro (like Safari or iTunes) have been failing to open while I'm working on another app. Restarting my computer solves the problem, and the apps will then open; but it happens again later in the day. I still have around 30 GB of storage left, and when I run Disk repair, it says "disk repair complete" with no indication of anything being untoward. How do I fix this recurring problem? I have even done a disk repair from safe mode. I have Sierra (10.12.6), and I would prefer not to upgrade my system because certain 3rd party apps like Photoshop may not transfer to a new system.