The Lenovo Yoga 3 is a 64 bit machine. I am running the 32 bit version of Firefox. There is a 64 bit Firefox but it seems to be compatible only with Windows 8/7.

Could running a 32 bit Firefox on a 64 bit laptop be the problem. If so, would the Windows 8/7 version of 64 bit Firefox run under Windows 10?

I am writing this in a Chrome browser because it was difficult to write this post in Firefox.

I suggest sticking with 32-bit Firefox for now. The 64-bit version doesn't get much testing and since you already have a brand new OS in the mix, it might just be too difficult to troubleshoot...

Firefox 40 was released today and it has numerous compatibility fixes for Windows 10. Probably not relevant to Flash, but might help with other things. You usually can trigger the update using Help > About Firefox. It's also downloadable here: https://www.mozilla.org/firefox/all/

This is some standard guidance that addresses the most common issues with the Flash Player plugin. I'm sure you've seen some of it before, but just in case:

(1) If you have any recorders/downloaders that interact with Flash media make sure they are as up-to-date as possible, or disable them temporarily.

(2) Disable hardware acceleration in Flash: right-click the media in the player and choose Settings, then the first mini-tab and uncheck the box to use hardware acceleration.

More information in this support article from Adobe: http://helpx.adobe.com/flash-player/kb/video-playback-issues.html#main_Solve_video_playback_issues

(3) Disable protected mode (Windows Vista and higher)

The protected mode feature of the Flash player plugin has security benefits, but seems to have compatibility issues on some systems. You can disable it using the Add-ons page. Either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. On the right side, find "Shockwave Flash" and click the More link. Then uncheck the box for "Enable Adobe Flash protected mode" and try that for a day to see whether it helps.

Also, thank you for sending crash reports. You can share that data with forum volunteers to see whether it points toward a specific solution. Please check the last section of the support article "Firefox Crashes" for steps to get crash report IDs from the about:crashes page, and then post some of the recent ones here.

And finally, while you are troubleshooting this, it might be helpful, to avoid unnecessary pain on sites where Flash is not actually essential, try setting Flash to Click-to-Play ("Ask to Activate"). This will delay Flash from starting on a page until you approve it.

To set "Ask to Activate", open the Add-ons page using either:

• Ctrl+Shift+a
• "3-bar" menu button (or Tools menu) > Add-ons

In the left column, click Plugins. Look for "Shockwave Flash" and change "Always Activate" to "Ask to Activate".

When you visit a site that wants to use Flash, you should see a notification icon in the address bar and usually (but not always) one of the following: a link in a black rectangle in the page or an infobar sliding down between the toolbar area and the page.

The plugin notification icon in the address bar typically looks like a small, dark gray Lego block. (When the page wants to use a blocked plugin, the icon turns red to alert you to the concern.)

If you see a good reason to use Flash, and the site looks trustworthy, you can go ahead and click the notification icon in the address bar to allow Flash. You can trust the site for the time being or permanently.

But some pages use Flash only for tracking or playing ads, so if you don't see an immediate need for Flash, feel free to ignore the notification! It will just sit there in case you want to use it later.

Not a solution for crashes, not even a workaround, but perhaps will avoid needless suffering.

Here are the 5 latest crash reports: bp-96b7ec94-bc02-423c-84dd-505be2150811 bp-4470f720-ee21-4ddc-bd51-29e642150811 bp-31ec812a-6dfd-438d-8da8-9cb7e2150811 bp-df52e4a8-5b76-457a-bd85-c6cb12150811 bp-47e62e82-ad55-4dd8-9a56-c604f2150811

Those reports match up with a lot of different Flash-related problems, so I don't have any specific advice to add to my earlier "standard guidance":

https://support.mozilla.org/questions/1076607#answer-765898

Does that help at all?