It's odd because I had previously been able to find and install the SAMD Board package the other week. At some point it seemed to have disappeared as a option in my IDE (1.8.9) for when I try to select a different board. None of the SAMD boards are populating in the IDE even when the associated files are in the relevant sub-solder of the Arduino 15 folder.
After taking a few hour break from troubleshooting this problem I came back to the IDE and was able to download and install the SAMD Boards via the Board Manager. When I opened the IDE today it seems as in the SAMD Boards are gone and the Board Manager gives the error message above when it tries to download them. I'm not really sure what's going on here.
This error doesn't happen when I open the Library Manager.
I've tried restarting the computer, uninstalling and reinstalling the IDE, and deleting relevant folders within Arduino 15 based on other forums I've seen.
In the Arduino IDE, click the link on the line following File > Preferences > More preferences can be edited directly in the file. This will open the Arduino15 (or similar name depending on OS) folder.
Delete all files from the Arduino15 folder except for preferences.txt. Please be very careful when deleting things from your computer. When in doubt, back up!
Restart the Arduino IDE
Tools > Board > Boards Manager
Wait for the downloads to finish
Click the "Close" button
What happens sometimes is there is some glitch during the download of https://downloads.arduino.cc/packages/package_index.json and the IDE isn't smart enough to clear out the bad files after that happens so you get stuck in this state where the download can never be verified. Manually clearing the files solves that (unless the glitch happens again, but that should be a rare occurrence).
speidenr:
Maybe there is another way to download and set up this?
You can manually download https://downloads.arduino.cc/packages/package_index.json to your Arduino15 folder. The problem is that will only get your boards back until the next time the Arduino IDE attempts to download the file and fails the verification again. The Arduino IDE deletes the old copy of the JSON files when downloading the new ones. The JSON file is required for the boards installed via Boards Manager to be recognized, so if you ever have a failed/corrupted download then the boards disappear (even though they're still installed perfectly). So to work around this issue, you would need to figure out how to block the Arduino IDE completely from attempting downloads of the JSON file. Perhaps you could set your firewall to block the Arduino IDE from connecting to the Internet (it won't initiate the download if it doesn't have a connection).
It would be worth opening Arduino15/package_index.json.tmp in a text editor to see whether you can see anything corrupted about it.
Recently someone reported a similar problem and it turned out they were behind a corporate firewall that was injecting a warning message into the downloaded files.
I am also having this same problem with 1.8.9. Under 1.8.7 my Due worked fine (although I was using the non admin install then and am now using the Windows Installer).
I have uninstalled the IDE and deleted all Arduino directories (except my sketches and libraries), then reinstalled. When I start the IDE with my Due online I get a small message box prompt "Install this package to use your Arduino Due board". When I do so I get the error "https://downloads.arduino.cc/packages/package_index.json file signature verification failed. File ignored."
With the IDE closed, I have manually downloaded the package_index.json file into my Arduino15 directory. When I restart the IDE the same message box prompt is displayed and when clicked, the same error returns. Plus, the file that I manually downloaded is deleted.
The package_index.json file looks sensible (I'm no expert as to what it should contain).
Re firewalls, I'm using Windows 10 and have Norton 360 installed. Turning off its smart protection didn't fix my problem.
I know it's not a problem with the IDE since there hasn't been a new IDE release. I don't think it's a problem with the JSON file because it's working perfectly fine for many thousands of people. So I think it must be a network issue. It reminds me of a problem we had a little while ago where Cloudflare was sometimes requiring a Captcha to access the file in an effort to prevent malicious activity. Of course the Arduino IDE has no way of dealing with a Captcha. However, that caused a different error message.
Rename the downloaded files with a .txt extension (the forum software doesn't allow attachments with .json or .sig file extensions).
In this forum thread, click the "Reply" button.
Click "Attachments and other options".
Attach the downloaded files.
Post the reply
I'll check out your files and see if you're having the same problem as Cheetor is reporting in the other thread. Once we have the problem narrowed down and confirmed, I'll report it to the people at Arduino who can investigate further.
In the meantime, I followed the suggestion that there's a router problem. I tethered my PC to my phone and was successful in downloading the Due board package.
My internet link is 4G thru the same carrier as my phone (Vodafone NZ) so all I changed by using my phone was swapping the wifi router for my phone. But I don't know whether the phone's data is routed the same as the PC in the carrier network. My router is a Huawei B315
Hmmm. Both your .sig files and .json files are identical to mine. In the other thread, Cheetor's .json file was different but the .sig file was the same, which would explain the signature verification error. The interesting thing is that Cheetor is also in NZ.
My hypothesis is that the recent update to package_index.json didn't end up going out to all the servers in Arduino's CDN but the .sig file was updated on the servers that didn't get the update so this causes the verification failure.
It's possible that the problem may have resolved itself. I know it does take hours for files to propagate through the CDN. I'm not sure when the change to the package_index.json was made but the first report was a couple days ago and it shouldn't ever take that long. It's also possible that the CDN system dynamically changes which server you are routed to based on load, infrastructure, etc. so it's not only a matter of geographic location. If you connect your PC back to your normal Internet connection do you get the same verification failed error again?
Hi there,
we launched a CDN refresh, can you please verify if you are still experiencing the
"package_index.json file signature verification failed. File ignored"
error?
If yes please reply with geographical location and both headers and files.
Thanks!