Further Update:
Harman's link to AIR v33.1.1.502 has now expired, too.
I have asked Harman if they would be willing to re-upload a link to v33.1.1.385 (the last official working AIR runtime for Windows) but, until such a link is available, please download v33.1.1.385 from FileCroco using the following link:
https://www.filecroco.com/download-adobe-air/
The file from FileCroco is the official Harman release of AIR v33.1.1.385 (genuine, clean and safe to use).
I found the SHA256 hash for the 'AdobeAIR.exe' v33.1.1.385 file on a Harman web page archived by archive.org (search for "https://airsdk.harman.com/runtime" and select the page dated 26 January 2021) and it matches the SHA256 hash of the file from FileCroco.
Filename: AdobeAIR.exe
Filesize: 7,689,512 bytes
SHA256: d5c8659a712145cc19b4e23ff0c731c87fefc5c100d98c963a2689c5fd97a96c
Apologies, once again, for the inconvenience.
I hope it won't be too long before Adobe AIR is back on track as Harman certainly seem to have fixed the original problem with v33.1.1.502.