Xcode fails to start Loading a plug-in failed.

The issue is I believe I attempted an upgrade and because I am using the new Apple chip CPU architecture, and not Intel, I have the wrong version. So the question is how do I get the Universal App Quick Start version back?

Thanks,

Carl
/Applications/Xcode.app/Contents/MacOS/Xcode > Xcode12.0BugReport.09.19.2020
2020-09-19 14:38:08.058 Xcode[11382:191748] [MT] DVTPlugInLoading: Failed to load code for plug-in com.apple.dt.IDE.IDEiOSSupportCore (/Applications/Xcode.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin), error = Error Domain=NSCocoaErrorDomain Code=3587 "dlopenpreflight(/Applications/Xcode.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice
Referenced from: /Applications/Xcode.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore
Reason: no suitable image found. Did find:
/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture
/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture" UserInfo={NSLocalizedFailureReason=The bundle is damaged or missing necessary resources., NSLocalizedRecoverySuggestion=Try reinstalling the bundle., NSFilePath=/Applications/Xcode.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSDebugDescription=dlopenpreflight(/Applications/Xcode.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice
Referenced from: /Applications/Xcode.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

More Info:

This is the one I downloaded: https://apps.apple.com/us/app/xcode/id497799835?mt=12

I need the link for my Apple CPU computer:

Hardware Overview:

Model Name: Apple Development Platform
Model Identifier: ADP3,2
Processor Name: Apple A12Z Bionic
Number of CPUs: 8
L2 Cache (per CPU): 8 MB
Memory: 16 GB
Serial Number (system): private
Hardware UUID: private
Activation Lock Status: Disabled

I believe I found my answer.

For A12Z Bionic processor development, you have to go to the universal download page:

https://developer.apple.com/download/universal/

That's where the resources are. Not in the App Store


Universal App Quick Start Program
Overview
Resources
Apply
Resources


Xcode 12.2 beta

So after downloading and running the Xcode 12.2 beta from the developer.apple.com/download/universal. I'm still receiving the following error. So I will need some help:

/Applications/Xcode-beta.app/Contents/MacOS/Xcode

2020-09-19 18:53:57.325 Xcode[4040:113313] [MT] DVTPlugInLoading: Failed to load code for plug-in com.apple.dt.IDE.IDEiOSSupportCore (/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin), error = Error Domain=NSCocoaErrorDomain Code=3587 "dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture" UserInfo={NSLocalizedFailureReason=The bundle is damaged or missing necessary resources., NSLocalizedRecoverySuggestion=Try reinstalling the bundle., NSFilePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSDebugDescription=dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture, NSBundlePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin, NSLocalizedDescription=The bundle “IDEiOSSupportCore” couldn’t be loaded because it is damaged or missing necessary resources.}, dyldError = dlopen(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, 0): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

2020-09-19 18:53:57.325 Xcode[4040:113313] [MT] DVTAssertions: Warning in /Library/Caches/com.apple.xbs/Sources/IDEFrameworks/IDEFrameworks-17512.1/IDEFoundation/Initialization/IDEInitialization.m:355

Details:  Xcode failed its initial plug-in scan, error = Error Domain=DVTPlugInErrorDomain Code=2 "Loading a plug-in failed." UserInfo={DVTPlugInIdentifierErrorKey=com.apple.dt.IDE.IDEiOSSupportCore, DVTPlugInExecutablePathErrorKey=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSLocalizedRecoverySuggestion=The plug-in or one of its prerequisite plug-ins may be missing or damaged and may need to be reinstalled., DVTPlugInDYLDErrorMessageErrorKey=dlopen(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, 0): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture, NSLocalizedDescription=Loading a plug-in failed., NSFilePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin, NSLocalizedFailureReason=The plug-in “com.apple.dt.IDE.IDEiOSSupportCore” at path “/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin” could not be loaded.  The plug-in or one of its prerequisite plug-ins may be missing or damaged., NSUnderlyingError=0x15fd245d0 {Error Domain=NSCocoaErrorDomain Code=3587 "dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture" UserInfo={NSLocalizedFailureReason=The bundle is damaged or missing necessary resources., NSLocalizedRecoverySuggestion=Try reinstalling the bundle., NSFilePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSDebugDescription=dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture, NSBundlePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin, NSLocalizedDescription=The bundle “IDEiOSSupportCore” couldn’t be loaded because it is damaged or missing necessary resources.}}}

Function: BOOL IDEInitializePlugInManager(IDEInitializationOptions, NSError *_autoreleasing *)

Thread:   <NSThread: 0x15a629620>{number = 1, name = main}

Please file a bug at https://feedbackassistant.apple.com with this warning message and any useful information you can provide.

carl@Carls-Mac Xcode % 

I think we have the same problem...

I have the Apple Developer Transition Kit (Apple/Arm Silicon) with macOS Big Sur 11.0 Beta (20A5299w) and I am unable to get Xcode to work at all.

I tried to install Xcode, but it hung during the "Installing Components" phase when I first opened it. I then forcefully restarted the computer and now when I open Xcode I see the message Loading a plug-in failed. with the text: The plug-in or one of its prerequisite plug-ins may be missing or damaged and may need to be reinstalled.. Opening it via the Terminal.app shows:

Code Block 
/Applications/Xcode-beta.app/Contents/MacOS/Xcode ; exit;
2020-09-20 12:46:51.273 Xcode[637:9847] [MT] DVTPlugInLoading: Failed to load code for plug-in com.apple.dt.IDE.IDEiOSSupportCore (/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin), error = Error Domain=NSCocoaErrorDomain Code=3587 "dlopen_preflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice
  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore
  Reason: no suitable image found.  Did find:
	/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture
	/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture" UserInfo={NSLocalizedFailureReason=The bundle is damaged or missing necessary resources., NSLocalizedRecoverySuggestion=Try reinstalling the bundle., NSFilePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSDebugDescription=dlopen_preflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice
  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore
...

Reinstalling Xcode makes no difference, likewise I downloaded Xcode 12.2-beta and tried to run it, but I receive the same error. How can I get Xcode working on my Developer Transition Kit?

Still no usable resolution from this group... looking for help.

Having installed from this link:
https://developer.apple.com/download/universal/

This version of Xcode 12.2 beta still gives the same error:

Applications/Xcode-beta.app/Contents/MacOS/Xcode

2020-09-19 18:53:57.325 Xcode[4040:113313] [MT] DVTPlugInLoading: Failed to load code for plug-in com.apple.dt.IDE.IDEiOSSupportCore (/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin), error = Error Domain=NSCocoaErrorDomain Code=3587 "dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture" UserInfo={NSLocalizedFailureReason=The bundle is damaged or missing necessary resources., NSLocalizedRecoverySuggestion=Try reinstalling the bundle., NSFilePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSDebugDescription=dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

 Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

 Reason: no suitable image found. Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture, NSBundlePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin, NSLocalizedDescription=The bundle “IDEiOSSupportCore” couldn’t be loaded because it is damaged or missing necessary resources.}, dyldError = dlopen(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, 0): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

 Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

 Reason: no suitable image found. Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

2020-09-19 18:53:57.325 Xcode[4040:113313] [MT] DVTAssertions: Warning in /Library/Caches/com.apple.xbs/Sources/IDEFrameworks/IDEFrameworks-17512.1/IDEFoundation/Initialization/IDEInitialization.m:355

Details: Xcode failed its initial plug-in scan, error = Error Domain=DVTPlugInErrorDomain Code=2 "Loading a plug-in failed." UserInfo={DVTPlugInIdentifierErrorKey=com.apple.dt.IDE.IDEiOSSupportCore, DVTPlugInExecutablePathErrorKey=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSLocalizedRecoverySuggestion=The plug-in or one of its prerequisite plug-ins may be missing or damaged and may need to be reinstalled., DVTPlugInDYLDErrorMessageErrorKey=dlopen(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, 0): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

 Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

 Reason: no suitable image found. Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture, NSLocalizedDescription=Loading a plug-in failed., NSFilePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin, NSLocalizedFailureReason=The plug-in “com.apple.dt.IDE.IDEiOSSupportCore” at path “/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin” could not be loaded. The plug-in or one of its prerequisite plug-ins may be missing or damaged., NSUnderlyingError=0x15fd245d0 {Error Domain=NSCocoaErrorDomain Code=3587 "dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

  Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

  Reason: no suitable image found.  Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture" UserInfo={NSLocalizedFailureReason=The bundle is damaged or missing necessary resources., NSLocalizedRecoverySuggestion=Try reinstalling the bundle., NSFilePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore, NSDebugDescription=dlopenpreflight(/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore): Library not loaded: /System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice

 Referenced from: /Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin/Contents/MacOS/IDEiOSSupportCore

 Reason: no suitable image found. Did find:

/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture

/Library/Apple/System/Library/PrivateFrameworks/MobileDevice.framework/Versions/A/MobileDevice: mach-o, but wrong architecture, NSBundlePath=/Applications/Xcode-beta.app/Contents/PlugIns/IDEiOSSupportCore.ideplugin, NSLocalizedDescription=The bundle “IDEiOSSupportCore” couldn’t be loaded because it is damaged or missing necessary resources.}}}

Function: BOOL IDEInitializePlugInManager(IDEInitializationOptions, NSError *_autoreleasing *)

Thread: <NSThread: 0x15a629620>{number = 1, name = main}

Please file a bug at https://feedbackassistant.apple.com with this warning message and any useful information you can provide.

I have just got the DTK, downloaded the Xcode 12.2 beta from the link (https://developer.apple.com/download/universal/), but I'm still getting the same issue. Did anyone solved the issue?

Just got the new DTK, installed the Xcode Beta 12.2 from the link above (https://developer.apple.com/download/universal/), and I get the same issue - Xcode doesn't run. Has anyone solved the issue?
(Sry for the duplication - how can I delete one....?)

Having the same problem using Xcode 12.2 at https://developer.apple.com/download/universal/
Did anyone find a way around this?

On my MacMini (3 GHz 6-Core Intel Core i5) Xcode, Garageband an iMovie did not launch and opening a terminal window also issued the missing framework error.
I manually installed XcodeSystemResources.pkg, MobileDeviceDevelopment.pkg and MobileDevice.pkg in this order. These packages are found in the Xcode.app bundle Xcode.app/Contents/Resources/Packages/...
Now the Apps are launching. No idea if there are problems left.

I am having same issue with my DTK. Has anybody found solution? How can I get Xcode installed and running on my DTK?

I'm guessing no one found a fix for this? I'm stuck with the same issue.

Any solution, beside Xcode 12.2 from apple store, seems not to work, still saying missing plugins but not able to track the report in console, (this one crash when starting Xcode)

pplication Specific Information:
dyld3 mode

• Terminating app due to uncaught exception 'NSRangeException', reason: '* -[_NSArrayM insertObject:atIndex:]: index 4 beyond bounds [0 .. 2]'

terminating with uncaught exception of type NSException
abort() called

Application Specific Backtrace 1:
0 CoreFoundation 0x00000001878e7104 exceptionPreprocess + 240
1 libobjc.A.dylib 0x00000001c67ea5b8 objcexceptionthrow + 60
2 CoreFoundation 0x00000001879a79f0 -[NSCFString characterAtIndex:].cold.1 + 0
3 CoreFoundation 0x0000000187809068 -[NSArrayM insertObject:atIndex:] + 1080
4 AppKit 0x0000000184a25d00 -[NSSplitView(NSSplitViewArrangedSubviews) insertArrangedSubview:atIndex:] + 528
5 AppKit 0x00000001849d1528 -[NSSplitViewController updateSplitView:withBlock:] + 68
6 AppKit 0x0000000184b972f8 -[NSSplitViewController insertArrangedView:atIndex:] + 172
7 AppKit 0x0000000184b97234 -[NSSplitViewController insertWrapperViewIntoSplitViewForSplitViewItem:atIndex:] + 104

Problem:
Xcode fails to launch with following alert:
"Loading a plug-in failed. -- The plug-in or one of its prerequisite plug-ins may be missing or damaged and may need to be reinstalled."

I found the key to a solution here:
https://developer.apple.com/forums/thread/100026

In the Xcode app directory:
/Applications/Xcode.app/Contents/Resources/Packages

there are four packages:
CoreTypes.pkg
MobileDevice.pkg
MobileDeviceDevelopment.pkg
XcodeSystemResources.pkg

I had to open and install all of these packages to fix the Xcode launch failure. Then Xcode opens normally.

How my Xcode was damaged: After a macOS update, I ran Xcode and it needed to update it's components. That failed because of low disk space (my bad) and then I was getting the "Loading a plug-in failed." alert upon failing Xcode launches.

Perhaps Xcode code resolve this issue automatically in the future?

FWIW, I took my DTK out of the desk drawer today after 6-8 weeks of ignoring it because Xcode was broken with all this same crap. For the first time since getting it, I got the alert to upgrade the OS (Finally!!!), ran through the install, and now Xcode seems to be working. The irony was I was only hooking it up to remove my user profile and send this well running, but entirely useless doorstop back to them with a note saying "thanks for wasting my $500 with this broken-*** software" (more nicely worded than that. maybe. probably.)

Maybe I'll hang onto it a little longer now to play with it...

Maybe.

Literally zero of the options in this and about 100 other threads on the topic (or even tangentially related to the topic) had any effect at all. :\

This is probably the worst beta I've ever participated in. :(

And I've been doing this crap for 30+ years.