Mac OS 13.3.3 not updating
I have a mid-2012 MacBook Pro with 16GB's of ram, approximately 250 GB's of available storage on my 500GB hard drive, running iOS 10.13.2.
When the App Store notifies me that the update to 10.13.3 is available, I hit the update button. However, after the Mac completes its process, restarts and I sign in, a message box from the App Store shows in the top right, saying:
"Some updates could not be installed automatically."
When i hit the Details button, it says pretty much the same thing, (no further useful details). In that same message it says, "Click install to update". When I hit the "Now" button, the App Store updates window comes back up but this time it says, "No updates are available".
Each day App Store re-notifies me that the update to 13.3.3 is available. Each day I try the update with the same results as above. This has been going on since I tried updating to 10.13.3 for the first time on Jan 31st or so.
Suggestions please?
MacBook Pro, macOS High Sierra (10.13.2)