Issue installing from boards manager in new Arduino IDE

Tool arduino:avr-gcc@7.3.0-atmel3.6.1-arduino5 already installed
Tool arduino:avrdude@6.3.0-arduino17 already installed
Downloading packages
move38:avr@1.3.0
Installing platform move38:avr@1.3.0
Failed to install platform: move38:avr.
Error: 13 INTERNAL: Cannot install platform: installing platform move38:avr@1.3.0: extracting archive: Create file /Users/vikas/Library/Arduino15/tmp/package-3157564506/Move38-Arduino-Platform/libraries/Examples05/BrokenRainbow/Broken Rainbow Map.png: open /Users/vikas/Library/Arduino15/tmp/package-3157564506/Move38-Arduino-Platform/libraries/Examples05/BrokenRainbow/Broken Rainbow Map.png: permission denied

I’m not a windows person and this might break some stuff (if its the same as sudo on linux), but maybe try running arduino as administrator?
I just run arduino with sudo and that works for me. Just make sure it doesnt save to a file folder in like the root of your system.