Flash Player Crashing All the time! Help?

I'd recommend using the 64-bit Firefox Beta on Windows 10.  I've been sending people on Win10 to that version for a few weeks, and the anecdotal evidence indicates that stability is much, much better, particularly on Win10.

The 64-bit version of Firefox on Windows also provides a native NPAPI plug-in sandbox, so we don't have to use our sandbox.  Back in 2010, we effectively built a sandbox on the wrong side of the NPAPI interface because Mozilla wasn't interested in investing in plug-ins at the time.  We saw an increasingly serious threat landscape coming, with the rise of state-sponsored actors and increasingly sophisticated malware coming out of both organized crime and oppressive government regimes.  There are a number of disadvantages to that approach, but it was by far the lesser of the two evils.

Attitudes at Mozilla have matured over the years, and the engineering team involved in the sandboxing effort for 64-bit did a really nice job.  The native sandbox scheme is more efficient computationally, and because it's native, troubleshooting crashes and identifying ownership is now very clear-cut.

The other big contributor to instability tends to be graphics drivers.   Hardware acceleration is a double-edged sword.  You get much better performance and improved battery life, but we expose latent issues in the underlying drivers and hardware by exercising them.  When you're installed on 98% of machines, that reach shakes out a lot of stuff that might have otherwise gone unnoticed. 

Because Windows 10 is relatively new, and writing graphics drivers that are perfectly stable is a tremendously difficult job, we're seeing a natural uptick in driver-related issues there, which will shake out as the platform matures over the next year or two.

In the meantime, please work through the video troubleshooting guide.  In particular, see the part about disabling hardware acceleration.  If the issues go away, you know that it's time to either locate updated drivers, or to open a bug report with the GPU vendor.

https://helpx.adobe.com/flash-player/kb/video-playback-issues.html

If you're still stuck, please follow the directions in the guide on providing the dxdiag report and additional information about what you tested and saw, and I'll be happy to look into it further.  If you have a specific piece of content and steps to reproduce that consistently work, those allow me to be extremely effective at getting fixes pushed out.

Thanks!

The "modern" operating systems security policies are not as effective and as fail-proof as advertised. Due to this nuisance, software installed frequently cannot fully record every single "system permission" required to grand reasonable functionality.

I offer a suggestion to minimise crash occurrences:

1) Install all "critical' and "security" updates for the operating system;

2) Use the most stable video driver version (it is recommended to perform a cleanup (DDU) before upgrading);

3) Completely remove AIR, Flash and Shockwave web players (except for the stock Flash player);

4) Download the latest stand-alone installers for the web players and install them in this order:

    a) Shockwave

    b) Flash

    c) AIR

I have done so, and I have experienced Firefox 43.0.1 crash only when playing a video in Facebook so far. Testing continues until the next browser of plugin update.