Could there be a conflict between the three different cache-related extensions listed in your system details?

Cache Status :: Add-ons for Firefox
CacheViewer Continued :: Add-ons for Firefox
Empty Cache Button :: Add-ons for Firefox

Perhaps try disabling two of them and testing various combinations to see whether that makes any difference.

No there isn't. I said in my original post that I added the other cache-related add-ons after the fact, trying to diagnose the problem and see how they read the disk cache. The disk cache was not loading for at least a week prior to my installing those add ons about three days ago.

The only configuration change I have made in at least a month otherwise, besides weekly updating of currently installed add-ons, was to upgrade to 11.0 sometime in the past week-and-a-half. I'm not sure if this problem preceded the update or was coincident with it as I wasn't paying that close attention.

Also, Cache Status is the one I have had installed for the last two years or so, my base cache-related add-on that I've never had a probelm with. I installed it originally trying to manage Firefox's memory leak problem.

I will disable the new ones and toggle Cache Status, though not expecting the toggle to make a differnece. I did that already, prior to fully uninstalling and reinstalling it.

I don't read every thread here, but I have seen one or two in recent years where the cache behaved strangely and the poster eventually had to purge their cache folder using Windows Explorer in order to restore it to proper functioning. I don't recall the best procedure for that, but it would be a fallback option.

I looked at the code for the Cache Status add-on. It queries the browser's cache service after each page load. Could you check whether you have any errors displayed in Firefox's Error Console?

Ctrl+Shift+j to open the console
click the Clear button
load or reload a page
click the Errors button to filter the list

Anything look Cache Status or cache-related?

I can research that, but which cache folder is it and where is it located? Is it a Firefox cache folder or Windows cache folder? If the latter, is it user folder or system folder, then I might be able to find it from there. Or is it one of the json files?

I did say that I created a Cache folder in my Firefox profile, thinking that might be the problem. When I started hunting around I saw it wasn't there (I don't know if it is even _supposed_ to be there). As of now...well, I just checked and was expecting the profile/Cache folder to be empty, but it is gone, as in disappeared or deleted.

Unless I get any more suggestions I'll probably just try creating a new profile next (which I was trying to avoid). I'll report back here with my results, although I won't get to this until later tonight.

I refreshed this page and got a bunch of CSS warnings, nothing more. I loaded, then refreshed, Yahoo's home page and a Yahoo news page and got no errors, warnings or messages.

I've done a few other odd pages and am not getting any errors/warnings/messages, just a blank console. Wondering if errors, etc. are being repressed because the disk cache is compromised. It's strange not to get anything for a page. I've toggled all the filters back and forth.

To locate your cache folder(s), check the path here:

about:cache

On Windows 7, it is under "Local" AppData rather than "Roaming" AppData (where the heart of your profile resides).

Again, I don't know the recommended procedure for manual surgery, but you could try renaming the Cache folder (e.g., CacheOld) and see whether Firefox creates a functional new one at the next startup.

Okay, what I see there are two folders, OfflineCache and startupCache. If startupCache is not the disk cache folder should I create one and what is its name? (In the meantime I will create a Cache folder here and see what happens.)

The Cache folder that I said I had created (and that has now disappeared) was placed in the profile folder in the "Roaming" directory. I wasn't aware of this "Local" profile folder.

The "Cache" folder I created in C:\Users\...\AppData\Local\Mozilla\Firefox\Profiles\ProfileName disappeared as soon as Firefox closed out in Windows Task Manager.

I'm going to do a new profile. Hopefully if this is a disk cache redirect it wasn't changed external to Firefox (if that's possible). I wouldn't know where to find it and similar to FF I haven't installed any new programs or made any significant system changes in the last few weeks.

The big cache folder should be:

C:\Users\username\AppData\Local\Mozilla\Firefox\Profiles\ProfileName\Cache

If that's not there at all, is it possible that some extremely clumsy privacy software is removing/blocking it?

(If you have previous session history, then I don't think you are in permanent private browsing mode.)

Perhaps a new profile is good idea. Close Firefox and start up in the Profile Manager as described in Managing profiles. Any time you want to switch profiles, close Firefox and return to this dialog.

If the cache works correctly in the new profile, you could continue to diagnose your existing profile, or migrate key settings like bookmarks from your problem profile to the new one. See Recovering important data from an old profile.

About moving the cache folder, there is a hidden preference you can create for that, but your system details didn't show it, so I assumed it wasn't set. See this thread for more info: How can I move the location of Firefox's cache to another drive to free up space on Cdrive? | Firefox Support Forum | Firefox Help.

Before creating a new profile I explored the (agrressive) privacy software options you suggested:

I only run AVG which has been installed for several years. I disabled it temporarily, restarted FF and restarted the browser. It made no difference, which I didn't expect as it's installation long predated the problem.

Similarly, I have another program installed called Browser Protect. This was installed two months ago, again predating my problem. I closed its process via Windows Task Manager, disabled it in Windows services, unchecked it in Windows Start-up manager and disabled it in FF add-ons , then restarted FF and the system, etc. No difference.

I created a new profile. After the first time opening it there were two subfolders in C:\Users\username\AppData\Local\Mozilla\Firefox\Profiles\ProfileName - "Cache" and "startupCache". I figured "onlineCache" was not there as I hadn't configured the profile yet.

I then exported all my extensions and extension settings to the new profile via the FEBE add-on. Opened Firefox and the disk cache was still unloaded. Checked the AppData\Local folder and the subfolders were back to "offlineCache" and "startupCache". The "Cache" folder had again disappeared.

My next step was going to be creating a new profile and moving all settings into it manually, but on a whim I decided to reinstall FF 10.0.2 to see what would happen.

Surprise! The disk cache is now loading again, the about:cache page again shows a "Disk cache device" section and folder path, and the about:cache?device=disk is no longer blank and shows a list of cached entries (currently at 21 MB).

I guess I should have rolled back first, but anyway I would like your insight on what could be causing this behavior and what I can do to upgrade to 11.0 and still have the disk cache be functional. Again, I had no new software or configurations changes either on my Windows system or Firefox in general over the past two months, some I'm mystified as to what could be causing this.

Did you close Firefox 11 before importing the add-ons? In other words, can we confirm that Firefox 11 in a default state worked correctly on your system?

If you are refering to the new profile, I opened it only once after creating the profile, but in a separate action. In Profile Manager you get the option to start Firefox immediately after creating the new profile. I didn't, but declined and _then_ opened the new profile for the first time from Profile Manager. I could not tell if Disk Cache was working or not then as I had no add-on installed to monitor it from inside the browser. The only confirmation is that I saw the "Cache" folder where it would be expected in the AppData\Local subfolder.

The FEBE profile has to be _exported_ from a current profile to a new profile. It can't import into an open profile. Thus, my current profile was open, I selected and exported to the new profile, then I opened the new profile again _after_ the add-ons were loaded. There I was able to see via the Cache Status icon (it's on the Add-on bar) that Disk cache was again "Not Loaded Yet" and I checked and saw that the "Cache" folder had disappeared from the AppData\Local folder.

I'm in the middle of some other things right now but in a while I will clean install another profile and go into about:cache to see what if the Disk cache is present there.

This is what I've done, starting with v10.0.2:

1. Created a new profile, "Test" in FF10.0.2. Did not install any add-ons. Initially opened via Profile Manager (not opened immediately after creating). AppData\Local folder contained Offline and startup cache folders at first use. Disk cache created either upon first close or second open.

2. Upgraded FF to v11.0. I did this via downloaded exe on the desktop (the update last week when this problem started was done using the update feature inside Firefox).

3. Again opened and closed "Test". Still maintaining disk cache.

4. Created a new profile, "Test2". Opened from Profile Manager (not immediately after creating). Cache folder created after first close. The only differnce between this profile and that of "Test" is that it only has Cache and startupCache folders, however, I set this profile to not save history. The only other setting was to change the home page to Yahoo. No add-ons installed.

5. Opened my current profile (the one with the add-ons). This profile had a disk cache in v10.0.2. With upgraded FF v11.0 the disk cache is again gone and shows as "Not Yet Loaded" in the Cache Status monitor on the add-on bar. the folders in AppData/Local are back to OfflineCache and startupCache.

6. Opened my current profile in Firefox safe mode. Checked about:cache and about:cache?device=disk pages. The former only shows the offline and memory caches, the latter page is blank.

If you agree with me my conclusion is that there _is_ an add-on conflict, something that is not cache related, and this conflict only manifests with the upgrade to v11.0. the only way I'll be able to figure out what is to toggle the add-ons (ugh!). Just turning everything off in Safe Made is an artificial suppression that isn't doing anything to revert the state of the caches.

The other thing I can do first, which might be easier and was on the agenda before I reinstalled 10.0.2, is to create a new profile and copy the old profile data into it by hand. If I use FEBE to add the extensions in small groups of 5 or so it might be easier to pinpoint the problem than having all extensions installed and toggling.

This behavior is a feature, not a bug. When the "clear history when firefox closes" setting is selected, with the option to clear the cache too, the disk cache is completely disabled. See https://bugzilla.mozilla.org/show_bug.cgi?id=709262 for more info.

Took me a while to figure this one out.

So to be clear WhackADo, this disk cache not loading is a _Firefox_ feature, not a Cache Status bug, and Cache Status is just reflecting the feature? Have you had the same experience I did with Cache Status or just (what you thought was) another issue with a disabled disk cache?

In the meantime I am going to upgrade back up to 11.0, toggle some settings and see what happens. I never bothered with trying to find an extension conflict -- I just downgraded back to 10.0.2.

Also, thanks for the link. Another link to a conversation within the bug thread gave me a clue as to why my Firefox takes so long to close out in Windows Task Manager after I close out of the browser.

@lm108 Yeah i've been using cache status for a year or two and it has been very helpful, i thought initially that it was a cache status bug but when i checked the about:cache page the disk cache wasn't even listed. After that i started googling and found that bugzilla page.

Just out of curiosity what was the reason that Firefox takes such a long time to fully exit? I noticed the process hanging around in process explorer long after I'd exited.

Upgraded to FF 1.0, deselected Options - Priacy - History - "Clear History Whe Firefox Closes" - Settings...History - Cache.

Disk cache stays loaded and its parameters are visible in Cache Status and various About: Cache pages, thus the probelm had nothing to do with the Cache Status extension or other cache-related extensions.

Guessing I have to manually delete the cache everytime I close, which is sort of a hassle.

Also notice today that after finally successfully esoling this problem with Firefox 11.0 there is now v12.0 to upgrade to.

The link to this thread (https://groups.google.com/group/mozilla.dev.apps.firefox/browse_thread/thread/1fd478855b2cf34f/e645dd54985d042b?pli=1) is in the first comment of the bug report you cited. I don't know if this is the reason, but it seems plausible:

The first poster here writes:

"This option is present in Options > Privacy > History and it has many sub-options.

There are several problems with this option. The three biggest ones are:

1....

2. When Firefox does close normally, clearing these things from disk takes an unbounded amount of time, potentially several seconds or even over a minute. During this time, we have to either choose to block the UI, add copmlexity to the feature (and UI) to make it interruptable, or we have to leave Firefox running in the background to do the cleanup. (This last option would result in users getting the "Firefox is already running" prompt if they try to launch Firefox during the cleanup.) "

So I'm guessing from this that a reason FF sticks in processes so long is due to cleanup. I usually run sessions (meaning, keeping the browser open before closing out) at least one day or longer so I can see why it would take longer, despite clearing using Cache Status multiple times per session. For me it can take more than a minute, but I also always run multiple tabs and always open and close on anywhere from 10 - 20 tabs.

The only time I notice FF clears almost immediately is in the first few days after I have created a new profile (even with multiple tabs on open and close), then the background closing interval tends to build up over time. There may be another factor involved besides just the Clear History items.