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Here you can find hints and tips if you are having issues getting the SDK installer to work.
If you had installed a previous (pre-release) version of the installer app, you will probably get an AIR error because of the mis-matched certificates. If you see such an error, you may need to uninstall the installer before continuing.
Linux
Adobe no longer provide updates for their installer for the AIR runtime used by the installer, so clicking the installer badge may give an error, or the package it sends you will fail to correctly install. Workarounds to install the AIR runtime are listed here.
Debian based distributions (such as Ubuntu)
For 32bit systems
sudo ln -s /usr/lib/i386-linux-gnu/libgnome-keyring.so.0 /usr/lib/libgnome-keyring.so.0
sudo ln -s /usr/lib/i386-linux-gnu/libgnome-keyring.so.0.2.0 /usr/lib/libgnome-keyring.so.0.2.0
For 64bit systems
sudo ln -s /usr/lib/x86_64-linux-gnu/libgnome-keyring.so.0 /usr/lib/libgnome-keyring.so.0
sudo ln -s /usr/lib/x86_64-linux-gnu/libgnome-keyring.so.0.2.0 /usr/lib/libgnome-keyring.so.0.2.0
Then for either system:
download the Adobe AIR installer by running the following command:
Once downloaded, you need to add "execute" permission to the installer:
sudo chmod +x AdobeAIRInstaller.bin
The last thing to do is executing the Adobe AIR installer:
sudo ./AdobeAIRInstaller.bin
Confirm is installed once complete
dpkg -l|grep adobeair
should list 'ii adobeair 1:2.6.0.19170 i386 Adobe AIR 2'. You can now click the installer on the main download page and it should work fine.
(thanks to http://www.ubuntubuzz.com/2012/08/how-to-install-adobe-air-on-ubuntu-1204.html)
Fedora and other .rpm based system (such as CentOS)
Currently .rpm's of the installer are not available.
Follow the instructions above to install the AIR runtime, then there has been some success reported using alien to convert the .deb package and install that. You will find the installer in /opt if all went well.