Error while installing message!

That good news. It means that you may have some Login Items (System Preferences > Users & Groups > Login Items), LaunchDaemons or LaunchAgents that are interfering with your machine.

I'm not qualified enough to give you recommendations about the latter twos (the first one should be easy for you to check). I've seen users posting EtreCheck reports on this forum to help the contributors debug their issues. You can download the software from https://etrecheck.com, run it on your machine (Give it Full Access to get a full report) and post the report on this forum.

I'll take a look at it for my own erudition but I think Grant Bennet-Alder will be in a better position to give you advice.

Try rebooting in Safe Mode to see if the issue persists: How to use safe mode on your Mac - Apple Support. If the issue is gone, reboot in normal mode and test again.

Greetings topcop1!

From your post we see you are having some trouble with an error while installing message appearing on your device. We can certainly see how that would be confusing and want to help! So it looks like this is most likely related to an app trying to install and getting stuck, do you have any applications you recently tried to download? When you click on that prompt does it say a name in the top left corner of the screen for which application the prompt is from? That can help us narrow down where to look.

Have a great rest of your day!

Safe Mode can take a long time to do its job, certainly more than 15 min depending on how bad the state of your Mac is in. I would suggest trying again and let the Mac run for a couple hours, until it completes.

Not only Safe Mode checks your disk, as you mentioned when you performed First Aid, but it also gets rid of cache files. I have even seen posting of users having to run Safe Mode a couple times in a row for recalcitrant issues.

topcop1,

Thanks for following up with us on this issue! Try checking to see if any applications are updating on that device currently as well, as they can sometimes be working in the background: Use the App Store to update apps on Mac.

Take care!

Having Safe mode takes that long suggests that your drive is accumulating Bad Blocks, and may die soon.

Be sure you have a Trusted backup, as you may need it VERY soon.

If you need advice about how to proceed, just ask, and Readers will be happy to provide more information.

When I say backups, I do not include ant Web-based sharing services like backblaze. "On the cloud" is great for sharing photos, but is not a viable backup solution for everything you have. The stuff is not under your control, and is subject to sloppy handling, arbitrary changes in policy, theft, data loss, and bankruptcy of the company that holds it. It can easily take three days to restore it at ordinary Internet speeds.

I am hoping you have a local, Disk based backup drive that you trust.

What Model MacBook Pro, by year, early mid Late, screen size?

Your Mac came with an SSD drive, not a rotating Magnetic drive that could be accumulating errors.

Since you made it through Safe Mode startup, you boot drive has had its directory repaired. That's good.

"works in safe mode, not in regular mode" implies, It's something you added.