I think the plugin checker site is a little befuddled by the new version numbers for Adobe Acrobat/Reader DC. If you open Adobe Reader and use Help > Check for Updates (or wherever that is now) and all is well,then feel free to ignore the plugin checker on that one.

For Flash, the site should be able to properly detect your version. Could you double-check it on my plugin lister page:

https://jeffersonscher.com/res/plugins.html

Does it say "Shockwave Flash (19.0.0.226)" ?

By the way, the "Updated Ad Blocker for Firefox 11+" extension is now very out-of-date compared with Adblock Plus.

And I think you only need one of these as they do the same thing (I don't have an opinion on which is better):

• YouTube Flash Video Player 41.0
• YouTube™ Flash® Player 1.4.0

Plugins are installed on system and not in Firefox. For it to say you have a older version of Flash Player even when you have installed the current it is usually because you have both installed on system.

https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-windows.html

Maybe try uninstalling all versions of Flash Player (plugin based) and install the current (plugin based) from https://www.adobe.com/products/flashplayer/distribution3.html while Firefox is closed.

Thanks! Your plug-in lister says that I have BOTH the new version and the old version of Flash Player:

• Name (Version): Shockwave Flash (19.0.0.185)
  Description: Shockwave Flash 19.0 r0
  File name: NPSWF32_19_0_0_185.dll
• Name (Version): Shockwave Flash (19.0.0.226)
  Description: Shockwave Flash 19.0 r0
  File name: NPSWF32_19_0_0_226.dll

But the Windows 10 "Uninstall or change a program" shows only the newer version, 19.0.0.226. Does this mean that the update process was sloppy, uninstalling the older version without deleting the file? I thought I should be able to answer that question myself by finding the folder that houses these files, but I can't find *either* file on my C-drive. In addition to searching the whole C-drive, I searched Program Files (x86) > Mozilla Firefox, and Program Files (x86) > Adobe separately, but couldn't find these files. (In fact, the Mozilla Firefox > Plugins folder seems to have precious little to do with my current plugins, and the Adobe folder only has Reader files in it, not Flash Player files.) Are these plug-in files hidden from an ordinary search? Is there a way for me to find them? If I find the 19_0_0_185 file, would it be safe or advisable for me to delete it?

For the Acrobat Reader, I checked as you suggested. Adobe says that the version I have is (a) up to date, and (b) the exact same version Firefox says is outdated, 15.9.20069.28170. So I think you're right about the befuddlement of Firefox's plug-in checker for Acrobat Reader DC.

For the YouTube players, I do indeed have both the ones you mentioned: YouTube Flash Video Player 41.0 and YouTube™ Flash® Player 1.4.0. I'll experiment with disabling or removing one of them.

Thanks also for the tip about "Updated Ad Blocker for Firefox 11+". Not only do I have that ad-blocker installed, I also have "YouTube AdBlock" and "AdBlock for You Tube" installed. I don't recall whether I did this intentionally after reading reviews, or because I was failing to find that something that I thought I'd installed, was installed. I didn't notice till now that the ad-blockers are all listed under "extensions". I think that every now and then, I looked at the list of plug-ins, and noticed that I wasn't seeing an ad-blocker (even though I thought I'd installed one), so I went and installed another. I'll disable or remove all three of these and try Adblock Plus.

Didn't see your 7:41 post till after I'd sent my reply to your earlier help. I'll try your suggestions there and let you know if they work.

Yes, the Flash updater sometimes leaves the old version if Flash is in use on a tab in Firefox. The official way to clean up multiple versions is the use Adobe's uninstaller and then reinstall just the latest. But as a shortcut, it often works to just delete the old file from here:

C:\Windows\SysWOW64\Macromed\Flash

You just want to remove NPSWF32_19_0_0_185.dll and leave the others.

Thanks again! The Flashplayer uninstaller did the trick. I'd used it before for some other problem with Flash, but had forgotten all about it. Firefox now recognizes Flash Player as being up-to-date, your own plugin-lister shows only the ...226.dll version, and when I look in C:\Windows\SysWOW64\Macromed\Flash , NPSWF32_19_0_0_226.dll file is there but not the ...185.dll file.

Windows' previous failure to find these two dll files when I searched the C-drive still surprised me, so now that I know where the current file is, I did some experiments. Searching the C-drive itself doesn't turn up NPSWF32_19_0_0_226.dll , but a search of C:\Windows or anything further along the path does find the file. Strange. Does Windows do this deliberately to keep non-experts from messing with files they shouldn't be touching?

dgdg2000 said

Searching the C-drive itself doesn't turn up NPSWF32_19_0_0_226.dll , but a search of C:\Windows or anything further along the path does find the file. Strange. Does Windows do this deliberately to keep non-experts from messing with files they shouldn't be touching?

Probably. Regular full disk searches exclude hidden and system files.