unwanted software FORCED INSTALATION by adobe

I've personally followed up on several dozen reports like this.  Given sufficient information, I am always happy to follow-up again.

That said, every time I look at this, it consistently comes down to a situation where a third-party browser plug-in (ad-blocker, anti-tracking plugin, etc.) caused the JavaScript on the page to execute in a way that was different than what was actually written (e.g. they blocked the UI with the opt-out), or the software was downloaded through a third-party UI (a browser add-on manager, etc.), which linked directly to the assets that had the optional bundled offers.

In general, the following always works:

• Always get Flash Player directly from Adobe, at https://get.adobe.com/flashplayer/
• If you use browser plug-ins that interfere with the normal operation of the page, you'll want to whitelist them or disable those plug-ins temporarily

Once you have Flash Player installed, you can completely avoid this workflow (and the possibility that any bundles get installed), by doing the following:

• Choose Allow Adobe to Install Updates (recommended)
  Future updates to Flash Player will be installed automatically.  You'll never see a bundled offer unless you need to reinstall.
• Use a browser that includes Flash Player as a built-in component
  In these instances, there's nothing to install, and updates are handled by the browser or operating system
  • IE and Edge on Win8+
    Both include Flash Player as a built-in component, and updates are delivered through Windows Update
    There's nothing separate to download or install
  • Google Chrome on all platforms
    Flash Player is a built-in component of Chrome.  Updates are delivered by Chrome's update mechanism

In the very unlikely event that you encounter a situation where the wrong payload was deployed (i.e. you opted out, but got the bundled offer anyway), I'd be more than happy to investigate.

The following information, and your geographical location would be helpful.

Adobe uses a global Content Distribution Network (CDN) to deliver content.  Knowing the geography and language in play might help me track down any highly localized problems with a specific CDN node or translated page.

The following information about your environment is also always helpful and appreciated:

https://forums.adobe.com/thread/1195540