On support site how does one reacjh he link to download the Mobile API Gateway Vesion 4.2 ... seems to be a challenge today
If you search for just "Mobile" are you able to find it? If not this may be an issue with the underlying entitlements.
We can get the web support team involved if that is the case to review.
Notice the hyphen in the name: CA Mobile - API Gateway. If you happen to be a fast typer and type "Mobile API Gateway" it doesn't show up. However, as mentioned, just typing "mobile" should bring it up in the selection box. Good luck!