We have developed an Adobe Air application using Adobe Flash Builder 4.6 to be installed on Mac desktop and it is being distributed on our own website rather than on Apple app store. It was getting installed and running without any warning or error on previous versions of Mac OS.
But since Apple has introduced Mac OS Sierra application is not getting installed. Its showing "app can't be opened because it is from unidentified developer". I know user can still install the application by allowing it from Settings->Security & Privacy but that's not a good idea.
I did research on this and found that we have to purchase Apple developer account and then have to sign app and installer using certificates generated from Apple developer account.
I generated Developer Id and Installer ID certificates using apple developer accounts and installed these certificates on my Mac machine. Then I tried to generate signed native installer using Adobe Flash Builder 4.6 and certificate exported from KeyChain Access. Previously it was giving error "Error in creating native installer file:Could not timestamp. Request timed out.". I found solution for this error that it can be resolved by updating Air SDK. I updated AIR SDK and this error was resolved.
This time I got new error "Error creating native installer file: Packager internal error". I did research on this and found that I can achieve this by using ADT where I have to first self sign my app and then can apply Apple Developer certificate on compiled app. I was able to generate airi file and then dmg file successfully by following steps given at: https://forums.adobe.com/thread/1568459
But when I tried to install my application by downloading it from my website, Mac OS shown same message again. I need help from techies to be identified developer for our Adobe Air application so that it can be installed on Mac without any error or warning. So guys please help in achieving this.