How to fix Shockwave Flash crashing with vSphere Web Client 6.X

What happened?

It came as a surprise to me that a few of my production vSphere and vCenter environments all started exhibiting issues with the vSphere web client.
I tried on every browser, both Windows and Mac, but kept getting this message:

Accompanied by a friendly reminder that the page couldn’t render:

As noted by VMware, this impacts all versions of the Web Client.
Additionally, there is no known resolution, but a few workarounds exist that are detailed below.

Personally I chose to patch the pepflashplayer.dll for Windows Chrome.
you can find the download at the bottom of this article

It worked like a charm! I was back in the Web Client without even re-launching Chrome!

Symptoms

While logging in to the vSphere Web Client the flash plugin crashes with the following error:
Shockwave Flash has crashed.

Cause

This is a known issue with Adobe Shockwave Flash version 27.0.0.170, and affects all versions of the vSphere Web Client.
For more information see https://bugs.chromium.org/p/chromium/issues/detail?id=774862

Resolution

Currently there is no resolution.

To workaround this issue, use one of these options:

Download Flash Player 27 Beta, available at http://labs.adobe.com/downloads/flashplayer.html. Release Notes are available at, http://fpdownload.macromedia.com/pub/labs/flashruntimes/shared/air27_flashplayer27_releasenotes.pdfNote: This is a Beta build and used at your own risk.
Use an older version of Shockwave Flash. For more information see the Additional information section.

Alternatively, the HTML5 Client and vSphere Client (legacy) are available for most operations, dependent on vSphere version and feature availability.

Additional Information

Community forums have identified a workaround of replacing the pepflashplayer.dll file with an older version as well.

Caution: This has not been verified by Adobe. fp_27.0.0.159 is not the latest version, the latest Flash version is 27.0.0.170.

All versions previous to 27.0.0.170 are impacted with the Critical vulnerability CVE-2017-11292. See, https://helpx.adobe.com/security/products/flash-player/apsb17-32.html.

Windows Workaround for FireFox:

Click Start > run, type appwiz.cpl and click Run.
Uninstall Adobe Flash Player 27 NPAPI Version 27.0.0.170.
Download https://fpdownload.macromedia.com/pub/flashplayer/installers/archive/fp_27.0.0.159_archive.zip.
Extract the fp_27.0.0.159_archive.zip\27_0_r0_159\flashplayer27_0r0_159_win.msi.
Close FireFox.
Run the extracted flashplayer27_0r0_159_win.msi.
Click Start > run, type services.msc and click Run.
Disable Adobe Flash Player Update Service.
Open the vSphere Web Client in FireFox.

Windows Workaround for Chrome:

Download the attached 2151945_pepflashplayer.7z. [Link at bottom of post]
Extract the pepflashplayer.dll to the Desktop.
Open C:\Users\%username%\AppData\Local\Google\Chrome\User Data\PepperFlash\27.0.0.170\ in File Explorer.
Rename pepflashplayer.dll to pepflashplayer.old.
Copy the pepflashplayer.dll extracted earlier from the desktop to C:\Users\%username%\AppData\Local\Google\Chrome\User Data\PepperFlash\27.0.0.170\
Open the vSphere Web Client in Chrome.

Mac OS X workaround for Firefox:

Uninstall the current Adobe Flash Player. For more information, see https://helpx.adobe.com/flash-player/kb/uninstall-flash-player-mac-os.html.
Download the installer for Adobe Flash Player 27.0.0.159, available at https://fpdownload.macromedia.com/pub/flashplayer/installers/archive/fp_27.0.0.159_archive.zip.
Extract the flashplayer27_0r0_159_mac.dmg from fp_27.0.0.159_archive.zip\27_0_r0_159\.
Install Adobe Flash Player using flashplayer27_0r0_159_mac.dmg.
Disable automatic updates for Adobe Flash Player.

Download: