"Trust request error" 0xE8000003 when connecting iPhone to Mac

Question

When I connect my iPhone SE to my MacBook (Catalina 10.15.7) and open the Finder tab for the iPhone I am asked whether the Computer should trust this phone. When I click the button "Trust" I get the error:

Trust request error 0xE8000003

No connection is made.

This used to work nicely. I did however restore this phone from a backup.

I can connect this phone to other Macs. Also I can connect other phones to this Mac. Just these two don't want to get along in the Finder.

Btw, I can use the "Image Capture" app just fine!

How can I fix this?

---

Update:

There is this uncommented solution in the Apple forums, but running the first command:

sudo rm -rf /private/var/db/lockdown

already gives me a Operation not permitted even though the terminal has "full disk access" permissions. (When I temporarily disabled the system integrity protection via csrutil disable in the recovery console, I found that this folder is empty anyway.)

Update 2:

I see the following - maybe related - console errors when pressing the "Trust" button:

AMPDeviceDiscoveryAgent AMDeviceStartSession failed (0xE8000003) for device 0x7fcf0390820

nehelper    -[NWPrivilegedHelper startXPCListener]_block_invoke client pid 204 does not have any known entitlement
configd networkd_privileged_check_interface_settings_block_invoke received XPC_ERROR_CONNECTION_INVALID

AMPDeviceDiscoveryAgent AMDeviceCopyValueWithError failed (0xE8000016) for device 0x7fcf0390820
kernel  Sandbox: AMPDeviceDiscove(570) deny(1) mach-lookup com.apple.softwareupdated

Update 3:

When Xcode tries to connect with the iPhone, it fails and shows this in the details:

Failed to enable wireless functionality on the device.
Domain: com.apple.dtdevicekit
Code: 805
Recovery Suggestion: Please check the device connection and ensure that a passcode is set on the device.
User Info: {
    AssociatedMobileDeviceFunction = DTDKEnableWireless;
    DVTRadarComponentKey = 487927;
}
--
Could not allocate a resource.
Domain: com.apple.dt.MobileDeviceErrorDomain
Code: -402653181
User Info: {
    DVTRadarComponentKey = 261622;
    MobileDeviceErrorCode = "(0xE8000003)";
    "com.apple.dtdevicekit.stacktrace" = (
    0   DTDeviceKitBase                     0x0000000121dd093f DTDKCreateNSErrorFromAMDErrorCode + 220
    1   DTDeviceKitBase                     0x0000000121e09643 __39-[DTDKMobileDeviceToken enableWireless]_block_invoke_3 + 200
    2   DVTFoundation                       0x000000010510e29a __DVT_CALLING_CLIENT_BLOCK__ + 7
    3   DVTFoundation                       0x000000010510febc __DVTDispatchAsync_block_invoke + 1191
    4   libdispatch.dylib                   0x00007fff6fba56c4 _dispatch_call_block_and_release + 12
    5   libdispatch.dylib                   0x00007fff6fba6658 _dispatch_client_callout + 8
    6   libdispatch.dylib                   0x00007fff6fba8818 _dispatch_continuation_pop + 414
    7   libdispatch.dylib                   0x00007fff6fba7f16 _dispatch_async_redirect_invoke + 703
    8   libdispatch.dylib                   0x00007fff6fbb4957 _dispatch_root_queue_drain + 326
    9   libdispatch.dylib                   0x00007fff6fbb5097 _dispatch_worker_thread2 + 92
    10  libsystem_pthread.dylib             0x00007fff6fe009f7 _pthread_wqthread + 220
    11  libsystem_pthread.dylib             0x00007fff6fdffb77 start_wqthread + 15
);
}
--


System Information

macOS Version 10.15.7 (Build 19H2)
Xcode 12.1 (17222)

Answer 1

Firstly, you can try reseting Privacy and Location settings on your iOS device, as this removes the trust file on the iOS device with your Mac (as well as any other Macs/PCs you have trusted to connect to the iOS device). It will affect all your other privacy/location settings as well.

But, once this has been reset, you should be prompted to trust the iOS device when it reconnects to your Mac. Once the two devices have trusted each other, the plist file in the Mac's Lockdown folder should be overwritten with the new trusted plist.

If you really want to remove the lockdown plist manually, I am not too sure how Catalina works with the separate OS system partition, as I am on macOS Mojave. But on macOS Mojave, you need to have SIP disabled and remove the plist through rootless. Only do this if you are comfortable with using rootless. If you are not comfortable using rootless, reseting privacy and location settings on the iOS device should be more than enough.

However, if you decide to use rootless, you really shouldn't remove the entire lockdown folder, but rather the specific plist for the UDID associated with your iOS device.

You can find the UDID of the iOS device (when connected) in macOS's System Information>USB>Serial number. Alternatively, run the command system_profiler SPUSBDataType and look for the serial number for the iPhone. The iPhone should still show up in System information when it's physically connected via USB, even if you can't access it in Finder.

Once you have found your UDID, note it down (because the serial number doesn't contain a hyphen, but there is one in the UDID's plist filename).

Now you will have to go into rootless, which you can do through terminal using sudo su - command, and navigate to the lockdown directory (on macOS Mojave it's /var/db/lockdown) and list all the files in the directory, and look for the plist with a filename that matches your UDID of your iOS device (again there should be a hyphen in the filename somewhere).

You should then be fine to remove the file (still in rootless) using the rm command, you don't need to use sudo rm in rootless. For me (on Mojave), the command to remove the plist in rootless is rm /var/db/lockdown/UDIDnumber.plist.

When you are finished in rootless, remember to logout by pressing Control+D in terminal. Once again, don't use rootless if you are not comfortable with it. So, be VERY CAREFUL using rootless.

Let me know if this solves your problems. I know there's a few trust issue bugs with iOS devices connecting to some Macs (but not all?) or only when hotspot is turned on. But hopefully this won't be your issue.

Answer 2

What did help finally was the update to iOS 14.2.

Things just started to work again.