error while donloading stable/package_esp8266com_index.json

after a complete fresh installation (preferences also deleted) I got:

Fehler beim Herunterladen von http://arduino.esp8266.com/stable/package_esp8266com_index.json

(error while donloading http:// ...)

Is there someting I can / should do?

Is it a typo, a feature, a bug? :o

confused MHz

arduino.esp8266.com seems to be down at the moment.

EDIT: It's back in business now.