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Preference prevents videos on other sites from being played?

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Hey, I cannot watch anime on 9anime.to (clicking on a video doesn't work there) yesterday, when I was instructed to turn off the browser.tabs.unloadOnLowMemory preference. Is this the result of turning that preferemce off?

If so, is there a way to fix that problem?

Hey, I cannot watch anime on 9anime.to (clicking on a video doesn't work there) yesterday, when I was instructed to turn off the browser.tabs.unloadOnLowMemory preference. Is this the result of turning that preferemce off? If so, is there a way to fix that problem?

Chosen solution

Likely not. The browser.tabs.unloadOnLowMemory pref only prevents Firefox from suspending (unloading) tabs that haven't been used (visited) for a while and you are low on available memory.


If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block content (Adblock Plus, NoScript, Disconnect, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block content.

Firefox shows the shield icon at the left end of the location/address bar in case Content Blocking is blocking content.

  • click the shield icon for more details and possibly disable the protection

You can check the Web Console about what content is blocked

You can try these steps in case of issues with web pages:

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

  • hold down the Shift key and left-click the Reload button
  • press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
  • press "Command + Shift + R" (Mac)

Clear the Cache and remove the Cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Remove the Cookies" from websites that cause problems:

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data -> Manage Data

"Clear the Cache":

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data -> Clear Data -> Cached Web Content: Clear

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is is causing the problem.

  • switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
  • do NOT click the "Refresh Firefox" button on the Safe Mode start window
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Chosen Solution

Likely not. The browser.tabs.unloadOnLowMemory pref only prevents Firefox from suspending (unloading) tabs that haven't been used (visited) for a while and you are low on available memory.


If you use extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) that can block content (Adblock Plus, NoScript, Disconnect, Ghostery, Privacy Badger, uBlock Origin) always make sure such extensions do not block content.

Firefox shows the shield icon at the left end of the location/address bar in case Content Blocking is blocking content.

  • click the shield icon for more details and possibly disable the protection

You can check the Web Console about what content is blocked

You can try these steps in case of issues with web pages:

You can reload web page(s) and bypass the cache to refresh possibly outdated or corrupted files.

  • hold down the Shift key and left-click the Reload button
  • press "Ctrl + F5" or press "Ctrl + Shift + R" (Windows,Linux)
  • press "Command + Shift + R" (Mac)

Clear the Cache and remove the Cookies from websites that cause problems via the "3-bar" Firefox menu button (Options/Preferences).

"Remove the Cookies" from websites that cause problems:

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data -> Manage Data

"Clear the Cache":

  • Options/Preferences -> Privacy & Security
    Cookies and Site Data -> Clear Data -> Cached Web Content: Clear

Start Firefox in Safe Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration is is causing the problem.

  • switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
  • do NOT click the "Refresh Firefox" button on the Safe Mode start window
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I don't have any Extensions.

I did what you suggested, but the problem is still there.

I am deeply sorry for wasting your and the Support Staff's time.