IDE hangs on startup, with no error shown in logs

[ptillisch]

Hi @mtmr. I see the problem here:

@mtmr

2024-02-16 15:58:02 2024-02-16T06:58:02.763Z root ERROR Detected an error response during the gRPC core client initialization: code: 3, message: Error downloading index 'https://downloads.arduino.cc/libraries/library_index.tar.bz2': Get "https://downloads.arduino.cc/libraries/library_index.tar.bz2": dial tcp 172.64.144.12:443: connectex: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.

2024-02-16 15:58:02 2024-02-16T06:58:02.764Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Loading index file: loading json index file C:\Users\<username>\AppData\Local\Arduino15\package_index.json: open C:\Users\<username>\AppData\Local\Arduino15\package_index.json: The system cannot find the file specified.

2024-02-16 15:58:02 2024-02-16T06:58:02.764Z daemon INFO time="2024-02-16T15:58:02+09:00" level=info msg="Loading hardware from: C:\\Users\\<username>\\AppData\\Local\\Arduino15\\packages"

2024-02-16 15:58:02 2024-02-16T06:58:02.767Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Error loading hardware platform: discovery builtin:serial-discovery not found

2024-02-16 15:58:02 2024-02-16T06:58:02.767Z root ERROR Detected an error response during the gRPC core client initialization: code: 9, message: Error loading hardware platform: discovery builtin:mdns-discovery not found

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.