IDE hangs on startup: "discovery builtin:mdns-discovery not found"

[johnelec1]

The following problems were detected during the gRPC client initialization:

[platform-index] - code: 9, message: Loading index file: loading json index file /Users/johngeelen/Library/Arduino15/package_index.json: open /Users/johngeelen/Library/Arduino15/package_index.json: no such file or directory

[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:serial-discovery not found

[platform-index] - code: 9, message: Error loading hardware platform: discovery builtin:mdns-discovery not found

[library-index] - code: 9, message: Loading index file: reading library_index.json: open /Users/johngeelen/Library/Arduino15/library_index.json: no such file or directory

[UKHeliBob]

Welcome to the forum

Which version of the IDE are you using ?

[ptillisch]

Hi @johnelec1. On the first run after a fresh installation, Arduino IDE downloads some additional essential components from the Internet and installs them. If it can't install those components then the startup fails. So the computer must have access to the Internet on the first startup.

The errors indicate Arduino IDE is not able to access the Internet. If it is not already, please connect your computer to the Internet, close the Arduino IDE window, then start Arduino IDE again. This time it should start up successfully.

After that first run, an Internet connection is not required. However, there are some supplemental features such as "Library Manager" that have an inherent dependency on the Internet. Those features will not be usable while your computer is offline. But the essential functionality of editing, compiling, and uploading sketches will be available even without an Internet connection.

[johnelec1]

Thank you for your reaction.
My internet connection is okay.

I can work with the Arduino Cloude IDE but I cannot find why the local Arduino IDE on my MacBook Pro with Apple M1 processor does not work anymore.

The fault that I find in the Terminal output is index file is fault / not correct.

Herewith the terminal output I hope you can find the problem.

(attachments)

Terminal output.pdf (28 KB)

[ptillisch]

I see the problem here:

@johnelec1

2025-02-22T11:22:24.014Z config INFO Loaded CLI configuration: {"board_manager":{"additional_urls":[]},"directories":{"builtin":{"libraries":"/Users/j
ohngeelen/Library/Arduino15/libraries"},"data":"/Users/johngeelen/Library/Arduino15","user":"/Users/johngeelen/Documents/Arduino"},"locale":"en","netw
ork":{"proxy":"http://https//mcudude.github.io/MiniCore/package_MCUdude_MiniCore-index.json"}}
2

Background

Proxy Configuration

Some people connect to the Internet through a proxy server. When used in this type of network, Arduino IDE must be configured to use the proxy. For this reason, there is a "Network" tab in Arduino IDE's "Preferences" dialog.

Additional Boards Manager URLs

We install support in Arduino IDE for specific Arduino boards by installing board platforms via the Arduino IDE Boards Manager.

In addition to the platforms provided by Arduino for the official boards, the Arduino community has created hundreds more 3rd party platforms for a diverse array of boards. When we want to install one of those 3rd party platforms, we must add a package index URL provided by the platform developer to Arduino IDE's Additional Boards Manager URLs preference.

Problem

You got confused when you attempted to configure Arduino IDE for the installation of the 3rd party "MiniCore" boards platform and put its package index URL in the proxy configuration section of Arduino IDE's preferences instead of putting it in the correct location in the Additional Boards Manager URLs preference.

This causes Arduino IDE to attempt to access the internet through the MiniCore package index URL, which obviously will never work.

Solution

Normally we could fix a misconfiguration via the friendly "Preferences" GUI in Arduino IDE. However, since Arduino IDE won't start up it isn't possible to access the "Preferences" GUI. So it will be necessary to use an alternative approach to fix the misconfiguration. I'll provide instructions you can follow to do that:

1. Close the Arduino IDE window if it is running.
2. Delete the file at the following path:

   /Users/johngeelen/.arduinoIDE/arduino-cli.yaml
   

   • The .arduinoIDE folder may be hidden by default in your file manager and terminal.
   • Please be careful when deleting things from your computer. When in doubt, back up!

Now try starting Arduino IDE again. This time it should start up fully and be in a functional state.

If you still want to install MiniCore, you can now do that. This time, make sure to be very careful to follow the installation instructions exactly. If you have any questions or problems while doing that, just let us know here on the forum and we'll provide further assistance.