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!

Om de ûnderfining foar jo te ferbetterjen is tydlik de funksjonaliteit dan dizze website troch ûnderhâldswurk beheind. Wannear in artikel jo probleem net oplost en jo in fraach stelle wolle, kin ús stipemienskip jo helpe yn @FirefoxSupport op Twitter en /r/firefox op Reddit.

Sykje yn Support

Mij stipescams. Wy sille jo nea freegje in telefoannûmer te beljen, der in sms nei ta te stjoeren of persoanlike gegevens te dielen. Meld fertochte aktiviteit mei de opsje ‘Misbrûk melde’.

Mear ynfo

Dizze konversaasje is argivearre. Stel in nije fraach as jo help nedich hawwe.

How do I enable HTML5? I disabled it or blocked it by accident.

  • 2 antwurd
  • 4 hawwe dit probleem
  • 8 werjeftes
  • Lêste antwurd fan cor-el

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All the videos are blocked. For example, Youtube and Facebook videos. It only shows a black screen. Plus, only Flash works for now.

All the videos are blocked. For example, Youtube and Facebook videos. It only shows a black screen. Plus, only Flash works for now.

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install Flash plugin... such as adobe flash plugin

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You can check if there are media.*.enabled prefs that show user set (bold) on the about:config page.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

Use the Search bar at the top of the about:config page to locate preferences more easily: media.*.enabled


Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window