AIR package has no certificates at entry in AIR

Had a stupid Adobe AIR issue here that I couldn’t find the answer to online, so I’m posting it here for future reference. If you get the error

AIR package has no certificates at entry /path/to/META-INF/AIR/appdescriptor.xml; ignoring

when installing your AIR app, it it probably something wrong with your certificate. In my case, I installed the APK and after a little time I simply got the message “Application not installed”. I tried searching the usual sources, but didn’t find the right answers. Eventually I installed a “logcat” tool on my Android phone to view the logs on the device directly. There it was - something about the certificate apparently?

I pondered this for a while and then it dawned on me. I had thought that I could use the same “.p12” certificate file that I use for exporting AIR to iOS. Apparently, you can’t do this. You have to generate a separate “.p12” file (with no certification at all) for Android. So it’s not like Android will accept ANY .p12 file - only those that are random and are not based on an authenticated real user. Obvious, right?