There is no Adobe Flash Player on my computer, a 2009 Mac with OS X10.11. Trying to install it now, the installation doesn't even properly start and immediately shuts down with the message "Install of Adobe flash "unexpectedly shut down"" (it's in german). The same happens with the installation of Acrobat Reader. I really have no clue what else I can do different. I would be grateful for some advice on how to proceed. Thanks.
I'd like to get some log files from you to troubleshoot further. Please read through the FAQ Where do I find the Flash Player installation log on the Macintosh? and enable your system for verbose logging. Run the installer again and post all four files (install.log, FlashPlayerInstallManager.log, Adobe_ADM.log, and Adobe_GDE.log) in your reply, or upload them to cloud.acrobat.com using the instructions The specified item was not found..