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1. Download the installer (.deb) here: http://flex.apache.org/installer.html^{Image Removed}
   
   
2. Once you have downloaded the .deb, install it using dpkg (this command will force the installation, even if the AIR dependency is not resolved):

   Code Block
   sudo dpkg -i --force-depends apache-flex-sdk-installer-2.6.0-bin.deb

   
   
3. Once the installer has been installed (you might encounter several warnings and errors, just ignored them), open a terminal and go the installation folder:

   Code Block
   cd "/opt/Apache Flex/Apache Flex SDK Installer/bin"

   
   
4. Run the installer:

   Code Block
   ./Apache\ Flex\ SDK\ Installer

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Updating the SDK Installer

I really suggest that you uninstall the SDK Installer (but not the SDK, of course!) when you're done, because it will cause you all sorts of errors with apt-get in the future. Errors that look like this:

org.apache.flex.installapacheflex:i386 : PreDepends: adobeair:i386 (>= 1:2.6.0.0) but it is not installable
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

This can be done very easily with the following command:

sudo apt-get -f install