Arduino IDE .json Error when no internet access

I get the following errors when using my offline (no internet access) laptop.
"Error downloading https://www.teknic.com/files/downloads/package_clearcore_index.json"
"Error downloading https://downloads.arduino.cc/packages/package_index.json"

Makes sense why these errors occur since I don't have internet access. Can I manually download these files (from my desktop, which has internet access) and place them somewhere on my laptops local drive?

Not totally pertinent but I'm using a Teknic ClearCore microcontroller which uses an arduino wrapper.

Hi @mtellez2171. You can find the folder where you need to put the JSON files by doing this:

  1. Select File > Preferences from the Arduino IDE's menus.
  2. Click the link on the line following "More preferences can be edited directly in the file".

Note that it's under a folder that the file browser hides with the default settings, so you might have difficulty finding it if you are attempting to navigate directly to it via the file browser. But clicking that link will take you right to it no matter what.

Thanks pert... Before I tried your advice using preferences I thought perhaps if I connect to the internet once, to allow Arduino IDE to download whatever .json files it needs, I should be good to go later when my laptop has no internet. So I connected to the internet and the files must have been downloaded since I no longer received any errors but after disconnecting the laptop from the internet I got an error. This time only for the arduino .json file:

"Error downloading https://downloads.arduino.cc/packages/package_index.json"

I looked into the preferences to see where to change the URL to a local folder for the arduino .json file but didn't see that option anywhere in the preferences file. I did see the URL location for the Teknic .json file but that seems to be working after momentarily connecting to the internet. I attached a screenshot of the error I'm still getting when disconnected from the internet.

capture003

Are you experiencing any actual problems beyond the annoyance of seeing the error message?

I was getting a bunch of errors when I would upload a sketch to the board... I assumed these errors were related to the .json download errors that's why I started chasing those. It turns out those upload errors had something to do with the sketch I was uploading at the time. I just tried uploading a very simple LED blink program instead and it compiled/uploaded with no errors! I think that original sketch was corrupt? Anywho...that arduino .json download error still comes up in the Arduino IDE message box but I don't care, as long I can upload sketches. I also read somewhere (during this investigation) that firewall or security programs may cause the error I'm seeing. I've had other bizarre issues related to the protection software installed on this old Windows 7 machine. Thanks for your help!

I'm glad to hear it's working at a serviceable level.

My expectation is that the only real impact of this issue will be that you don't get notifications of new versions of the boards platforms defined in those JSON files. But you should be able to get updates on demand by connecting to the Internet and then running Tools > Board > Boards Manager, which will download the .json files and show you which have available updates.

You can also download them manually and add them to the folder I described before. In the case of https://downloads.arduino.cc/packages/package_index.json, make sure to also download https://downloads.arduino.cc/packages/package_index.json.sig, since this official index file is cryptographically signed. But Boards Manager will handle all that for you automatically.

If the error messages are annoying to you, you can disable the update checks in the IDE's preferences at File > Preferences > Check for updates on startup.