I'm getting this error trying to install Flex 4.5 on a MAC:
Beta or prerelease versions of Adobe Flash Builder are installed on the machine, and must be uninstalled before this installation can proceed. Please uninstall these products, restart your computer, then run this installer again.
I uninstalled Flex Burrito,
I have installed Flex 3 , Flash Builder 4, Adobe Flash CS5, BlackBerryTabletSDK-Air-Installer-0.9.4.201102222022.
What do I need to uninstall?
Same here. Searching my system for latent files related to "Flash Builder" show no results. Searching for "Burrito" revealed an uninstaller. I ran it and was able to install 4.5.
You can't simply delete the Flash Builder from Application folder from MAC.
The proper way to uninstall Flash Builder is using the uninstaller:
/Application/Utilities/Adobe Installers/Uninstall Adobe Flash Builder x.x
If you still have this folder in your machine, you can run the uninstaller and clean up the rest of the files.
Otherwise, you may install the same Flash Builder that you have installed on your machine and then run the uninstaller.
Just tried it on my MAC 10.7 and this fix the installation problem for me.