Clear the cache and the cookies from sites that cause problems.

"Clear the Cache":

• Firefox > Preferences > Advanced > Network > Cached Web Content: "Clear Now"

"Remove Cookies" from sites causing problems:

• Firefox > Preferences > Privacy > Cookies: "Show Cookies"

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 or otherwise make changes.

• https://support.mozilla.org/kb/Safe+Mode
• https://support.mozilla.org/kb/Troubleshooting+extensions+and+themes

Same prob and Nothing helps! Most of the tunes can be played absolutely with no problem and some of them just won't start :|

I have exact the same issue and tried to run Firefox 21.0 in Safe Mode. Still does not work!!!!

What's going on here Mozilla???? Suddenly, without installing anything new the last 4 days i can't play music on Soundcloud anymore. When using Internet Explorer i have no issues at all, but i won;t use that browser.

Adblock plugins does not matter, a week ago i could still listen music from Soundcloud and doing that for years already WITH Adblock enabled.

This issue just exist from the past days. Even cleaning cookies did not work, cleaned bmy whole system with Ccleaner, still no solution.

This issue is ONLY with Firefox, other browsers DO work, so this is a Firefox issue.

Yes the songs do play on Soundcloud but NO SOUND.

Try to clear the Flash local storage and settings.

Flash Website Storage Settings panel:

• http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager07.html

Global Storage Settings Panel:

• http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager03.html

Please update to the latest version of Firefox, (you have 18.0) that version is insecure and is not maintained anymore. If you don't want the fast 6 week release schedule, you can use Firefox ESR 17 and you can learn more about it here.

Ever heard of Ccleaner? It can clean your whole system, including LSO cookies (Flash). As said, i have cleaned my FULL system and it does not help anything. It still does not work. I'm using Firefox 21.0 and not 18.0 by the way....

This thread is about Firefox on Mac (at least the OP is on Mac), so programs for the Windows platform won't work.

I'm using WIndows 7 and have exact the same problem. This is a Firefox problem, nothing OS related.....