Adobe Air Installation problem on my Mac Book

Having trouble downloading Adobe Air to my Mac book (OS 10.7.5).

Irrespective of which browser I use, Safari, Firefox or Chrome after it initially appears to be downloading I get the same message

….."can't find the server at airdownload.adobe.com".

Tried removing all internet restrictions etc to no avail.

I see from other postings that there were issues installing Adobe Air in the past but none seemed to involve having trouble connecting to "air download.adobe.com"

I need Adobe Air to run Scratch 2.0.

Any ideas please?