Join the AMA (Ask Me Anything) with the Firefox leadership team to celebrate Firefox 20th anniversary and discuss Firefox’s future on Mozilla Connect. Mark your calendar on Thursday, November 14, 18:00 - 20:00 UTC!

This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

My tabs are crashing (Gah. Your tab just crashed.) Windows 10N

more options

I was getting errors while playing youtube videos : "Your browser does not currently recognize any of the video formats available"

I tried disabling addons and a bunch of other things that I saw googling through the error. I eventually uninstalled and reinstalled firefox to see if a clean installation would work. It didn't. I saw next someone mention that it might be a windows media issue and since I have Windows 10N I've had to download the Windows 10 Media Feature Pack before for something. I tried to download and reinstall that. Since then, it's gotten worse. My tabs how completely crash if there's any video on the tabs. They also possibly crash for other reasons, but I'm not sure (when I go to pages where I don't think there's any video, but who knows.

Crash report: https://crash-stats.mozilla.com/report/index/455b90e2-a0ed-4182-859b-78d610190217

It seems like there's something wrong with msvp9dec.dll, which seems to be a Windows file. I'm not quite sure what it is or what to re-install to fix it.

Any help would be greatly appreciated. Thanks!

I was getting errors while playing youtube videos : "Your browser does not currently recognize any of the video formats available" I tried disabling addons and a bunch of other things that I saw googling through the error. I eventually uninstalled and reinstalled firefox to see if a clean installation would work. It didn't. I saw next someone mention that it might be a windows media issue and since I have Windows 10N I've had to download the Windows 10 Media Feature Pack before for something. I tried to download and reinstall that. Since then, it's gotten worse. My tabs how completely crash if there's any video on the tabs. They also possibly crash for other reasons, but I'm not sure (when I go to pages where I don't think there's any video, but who knows. Crash report: https://crash-stats.mozilla.com/report/index/455b90e2-a0ed-4182-859b-78d610190217 It seems like there's something wrong with msvp9dec.dll, which seems to be a Windows file. I'm not quite sure what it is or what to re-install to fix it. Any help would be greatly appreciated. Thanks!

Chosen solution

hi, this should be a workaround to avoid the tab crashes: enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named media.wmf.vp9.enabled. double-click it and change its value to false, then restart firefox once.

Read this answer in context 👍 1

All Replies (7)

more options

bp-455b90e2-a0ed-4182-859b-78d610190217 Signature: Ndr64pClientInit

Crash Reason EXCEPTION_ACCESS_VIOLATION_WRITE

MSVP9DEC.dll = Microsoft Corporation

nvwgf2umx.dll = Dwm.exe = Microsoft Desktop Window Manager

This is for Sumo's Related Bugs 1521370 NEW --- Reproducible tab crashes after update to Windows 10 1809

more options
more options

FredMcD said

1521370 NEW --- Reproducible tab crashes after update to Windows 10 1809

This is a recent bug. Microsoft and Mozilla are working on the issue. From Bugzilla;

All crashes have the signature Ndr64pClientInit with crash reason EXCEPTION_ACCESS_VIOLATION_WRITE.

I went backwards in Firefox versions from 65 all the way to 50:

   Versions 56 and newer are crashing
   Versions <=55 are working

Modified by FredMcD

more options

Thanks for the tip. I tried a System file check. It did find corrupt files and repaired them, but it has not solved the issue.

Instead of downgrading to an earlier version of Firefox, I'll use Chrome instead until the issue is resolved. Thanks again.

more options

Sorry about that. But at least you fixed your system files.

more options

Chosen Solution

hi, this should be a workaround to avoid the tab crashes: enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named media.wmf.vp9.enabled. double-click it and change its value to false, then restart firefox once.

more options

philipp said

hi, this should be a workaround to avoid the tab crashes: enter about:config into the firefox address bar (confirm the info message in case it shows up) & search for the preference named media.wmf.vp9.enabled. double-click it and change its value to false, then restart firefox once.

This worked!! Thanks, very much appreciated. I'm assuming I'll be able to turn this back on once it's fixed?