Is updating by the Arduino IDE broken?

I had some problems here and couldn’t figure anything out so I decided to nuke arduino, reinstall and try again. Now I can’t even install the Kaleidoscope boards into the board manager.

Model 100 comes up with “CRC doesn’t match, file is corrupted. It may be a temporary problem, please retry later”. I’ve had similar problems with the IDE 1.8 and 2.0