You can fix this by modifying Firefox's configuration. In the address bar type: about:config

In the configuration screen search for string dom.storage.enabled and change the value to "true" by double clicking on it. Restart Firefox and enjoy!

Thanks for the tip! It works fine now.

I had the same problem with FF 3.6.12 running XP SP3. Could not send, reply or forward from gmail as of last week. Gmail forums and direct emails were no help. Your fix works for Windows too. Thanks!

We've contacted Google about this problem. They're rolling out a fix on their end within the week. Essentially, they are mis-detecting whether or not this feature is enabled when serving their sites.

Good news!

I have this same problem on a windows 7 machine. I checked the dom.storage.enabled and it IS set to true. If anyone has another fix for this I'd appreciate it.

I am suddenly having this problem with not being able to reply/forward to (certain Gmail conversations).

Now using, Mac OS 10.5.8 and experienced the presence of this issue with Firefox 3.6.10. AND 3.6.13 but not with Beta 4.

I have used Safari and the error is not reproducible. This issue is exclusively present to Gmail in FF.

I can confirm that FF config is presently dom.storage.enabled.

I have started FF in safemode, disabled, updated and enabled all plugins and add-ons, restarted FF and desktop many times, the issue is still present in FF 3.6.10/3.6.13.

Only some conversations cause this error. When I click on particular conversations reply/forward tab, the page freezes and the only way to temporarily resolve this, is to click the refresh icon as F5 will not work.

It does not freeze the whole FF browser, just the window with Gmail.

I need a fix as FF is my primary browser.

Thanks in advance! :-)

• "Clear the Cache": Firefox > Preferences > Advanced > Network > Offline Storage (Cache): "Clear Now"
• "Remove the Cookies" from sites that cause problems: Firefox > Preferences > Privacy > Cookies: "Show Cookies"

Thanks, however this did not help. I have cleared everything, same issue is occurring.

'Posted December 16, 2010 7:41:11 PM PST:

   * "Clear the Cache": Firefox > Preferences > Advanced > Network > Offline Storage (Cache): "Clear Now"
   * "Remove the Cookies" from sites that cause problems: Firefox > Preferences > Privacy > Cookies: "Show Cookies" 

This is not a fix.

I already had that setting. Nothing to improve.

Still have the problem.