Finder Can't Quit: iOS Activity in Progress

[Xairbusdriver]

Last few weeks, I have been getting a warning dialog stating that "Finder can't quit..." because some iOS action is in progress. Force Quit shows nothing open except Finder. Relaunching Finder is of no help; still can't shutdown the Mac. I end up having to use the "nuclear" method: hold the power button until all the monitor light leaks out! Of course, there is no automagic restart in the morning because of the non-standard shutdown.

There is an iPhone and an iPad in the "Locations" area of the Finder Sidebar. The eject button is replaced by the spinning arrow. "OK, the iPhone is the 'iOS' piece of the puzzle; but what is the process and why is it running?" Disconnecting the usb cable and even shutting down the iPhone changes the inability to shut down the Mac.

I've found the following "solutions" that I will try the next time this happens. Now, all I need is a way to remember what I'm not supposed to forget!

MacReports
Open Activity Monitor on your Mac (Applications > Utilities).

Search for AMPDevicesAgent. It may also help to sort the % column

Two (to four) processes should appear, a process and a helper agent pair. Highlight all of them and select the X on the far left top of that window. Then select Force Quit. Wait a moment. You may have to do do this once more.

If this problem occurs again, try starting your Mac in Safe Mode. This may fix your problem. Here is how:
• Shut down your computer.
• Press the power button and immediately press and hold the Shift key.
• Release the Shift key when you see the login screen.
• Login (you may have to log in more than once).
• Now your computer is in Safe Mode.
• Test to see if your problem repeats in Safe Mode too.
• Regardless of the result, restart your Mac normally, without pressing the Shift key.

HowToGeek:
• Safe Boot: With the Mac shutdown, hold down the shift key and press the power button. Hold the shift key down until you see the Log In screen. Now perform your favorite maintenance tasks.
• Reset SMC and/or PRAM/NVRAM:
1. With the Mac *shutdown*
2. Press the power button and immediately press and hold down the option + command + P + R keys.
3. The resetting routine may take as long as 20 seconds.
4. After that time, release the keys and the Mac will startup normally.

If you'd like to try some Terminal tasks you are welcome to read ths "Reader Rick" suggestions at AppleToolBox. I have not tried those specific commands/steps.

[jchuzi]

Can you access the crash log in Console? I did that last week when the whole Mac froze and it revealed that the culprit was AVG antivirus. I had noticed that apps were slow to open and wonky but didn't attribute it to AVG or anything else. I uninstalled AVG and now everything is back to normal.

Warning: AVG antivirus IS a virus.

[Xairbusdriver]

I've not checked the Console yet since the answers fit the problem so well. Plus, Apple made using Console much les user-friendly in Catalina macOS 10.15 and carried that forward to Big Sur macOS 11.

I've heard that warning before.

[Xairbusdriver]

It happened again last night. Fortunately since Finder was still running, I could open Activity Monitor and kill the four processes with "AMPD" as the first letters of their names. One or two had to be "killed" multiple times because they restart automatically. I think because Finder keeps calling them in an attempt to Sync either or both my iPhone and iPad.

Just opened Console (finally ) and found hundreds of entries for "AMPDevicesAgent" and "AMPDeviceDiscoveryAgent" about every 3 to 10 seconds.

A DDG search found at this:

What is AMPDevicesAgent?

AMPDevicesAgent in Catalina is a new background daemon in macOS Catalina responsible for synchronisation of iOS devices using Finder. This functionality was split from iTunes in Catalina, and such helper code has been split into different daemons, such as this one. AMPDevicesAgent is located at:

/System/Library/PrivateFrameworks/AMPDevices.framework/Versions/A/Support/AMPDevicesAgent

Changed my Finder Sync settings:

• Backups:
• Back up ... to this Mac
• Options:
• DIS-abled "Show ... when on Wi-Fi"

I also used a Terminal command that "Disable iPhone syncing in Finder". It did remove the iDevices from the Finder. But that made it very difficult to actually Sync the now invisible hardware.

I think I will try another defaults write command that may be less 'nuclear'... we'll see. There is yet another pkill command that will just stop the processes until the next start up... Actually, I think things are stable and working without the use of Terminal... if it ain't broke, don't "fix" it!

[Xairbusdriver]

Observations: Syncing and/or Backups
(with manual device syncing only, Wi-Fi syncing disabled):

AMPDeviceDiscoveryAgent

• Runs as long as the Mac is running. Mainly waiting to be called by Finder.
• Insignificant % CPU (0.0)
• < 3MB memory

AMPDevicesAgent

• Runs as soon as Finder 'notices' an iOS device is plugged in.
• Insignificant % CPU (0.0)
• ~ 30MB memory.

Possible bug? Finder gets 'confused' when iOS device is connected via cable and Wi-Fi?