I tried to download the ATmega16 board in my Arduino. I have set below URL under File->Preference->Additional board manager URL
https://mcudude.github.io/MightyCore/package_MCUdude_MightyCore_index.json
I am getting below attach images. How can we resolve this error and install atmega16 board manager?
I am using Arduino version 1.6.9. I don't have any issue in opening MightyCare and Arudino URL from my chrome browser.