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I cannot clear the cache completely.

  • 27 replies
  • 13 have this problem
  • Last reply by StevenCee

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OMG! This has been a nightmare trying to ask this question. Every button or link kept me in a closed loop of meaninglessness!

QUESTION : Suddenly last night and today, I am unable to completely clear the Firefox browser cache. Can someone please tell what is going on? Thank you!

Chosen solution

Well, gentlemen, suddenly I have this problem no longer. The other evening as I was shutting down Firefox, following a good browsing of the Internet, Firefox continued active for quite some time, not completely disengaging though the window closed. After a long while, wishing to turn the computer off, I "force quit" the application, and shut down. Since that night, I am able to clear the browser cache completely, whenever I choose. The 437Kb have "gone away", and I have no idea why. Thank you, both, for the conversation and assistance.

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All Replies (20)

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I've been having the same issue. It will work if you click on it, sometimes hold it down for five or so seconds, etc, and it will slowly whittle itself down, sometimes you can luck out, and there'll be some big leaps as well as the tiny steps. It's a pain, and a bug, as others have this same thing going on....

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There may be two separate problems:

(1) The clearing of the cache stops prematurely without notice; and/or (2) The page fails to update with the new size.

If nothing seems to be happening at all after a few seconds, try reloading the page (Command+Shift+r) to get an updated report on the size of the cache on disk.

Also, perhaps it makes sense to check for any error messages in the Firefox's Browser Console. I suggest opening the console BEFORE trying to clear cache. You can do that using either:

  • menu > Developer > Browser Console
  • Command+Shift+j

After it opens, click the Clear button along its top bar to declutter the console and either minimize the window or switch back over to your Preferences page. After clicking the Clear Now button, if it doesn't do what it should do, check the Console for any error messages.

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By the bye, I am on an iMac, running OS X El Capitan 10.11.4

Stephen Cee, thanks, but I am aware of that, and I just keep hitting "CLEAR" until it's all gone. Annoying, but whatever. However, in this case, no matter how many times I hit, or how long I 'hold down' the button, it only goes down to 437Kb.

Jscher 2000, I have reloaded the page. I have quit Firefox and re-opened. I have quit and re-started the computer. I have done so and completely shut down the machine, waited, and re-booted.

I do not have the expertise to meddle within the Developer realm. I know not what to look for, nor what to do if I were to stumble upon something. Is malware a possibility? Is there a way to override what is continuing its hold on my browser?

Also, I just had a major update from Apple for El Capitan. It had loaded in the background (which I COMPLETELY hate) and was waiting for my approval to complete when the first instance of 437Kb occurred.

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Hi IamProspero, you do not need to be a developer to see whether an error message appears. Even if the error message is incomprehensible, it would be useful to copy/paste it here if one appears. I have zero chance of getting my hands on a Mac, so we'll need all the clues we can gather.

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OK, jscher2000. Let me try. What am I looking for that I should copy?

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Here's what I currently see :

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IamProspero, if your cache gets down to 437kb, that's almost nothing, not even half a megabyte, and it's natural for it show a tiny bit, since as soon you zero it out, it's automatically caching new stuff. So, I wouldn't sweat it, if that's your biggest problem..

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The best way to isolate related errors is:

(1) Open the Browser Console (2) Use the Console's clear button remove existing console messages (3) Load the Preferences page (4) Check the Console for any new messages related to the page load (5) On the Preferences page, click "Clear Now" (6) Check the Console for any new messages related to clearing cache

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Hmm, in the old days when I used Clear Now, Firefox would freeze for a time; with a slow, congested hard drive, I have waited as long as 15 seconds. Now, it seems to run completely differently. When I didn't see 341MB drop after 5 seconds, I reloaded the page and got 67MB or 76MB. I thought about that for a few moments and reloaded again, and then got 0MB. Some kind of progress bar would be really useful if this behavior of running asynchronously in the background is the new normal.

Note: I use Windows 7, in case this is a platform difference.

Modified by jscher2000

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Much thanks to both of you, StevenCee and jscher2000, and I will attempt the steps you recommend. Yes, 437Kb is a pretty small amount, but it's more than zero which is what I prefer and what I have been able to achieve *for years*. The change is what disturbs me. Something new is afoot, harmless or not. I don't want anything on my computer, I don't want anything *running* on my computer, of which I am unaware and that I have not sanctioned. I am rather uncomfortable with programs running in the background. Nothing, of which I am aware, on my computer updates without my immediate and particular consent. I know : TMI.

What if I were to uninstall Firefox, then re-install it? Does that sound reasonable?

Modified by IamProspero

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Gentlemen, is this anything about which to be concerned?

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So, I followed your suggestions, jscher2000, and I still only get down to 437Kb with the following report on the Browser Console.

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Hi IamProspero, I don't think the NVIDIA message is related to cache. Almost certainly a coincidence.

To see what is using 437KB, could you open the following internal page: type or paste about:cache in the address bar and press Enter to load it.

The "Disk" section is the relevant one. There should be a link to view the stored items. If there is a zero item count but space is still being consumed, hmm, you could consider removing the whole cache (or is it cache2?) folder after quitting Firefox and letting Firefox build a new one, in case there is a permissions/corruption issue there. Note: I'm not sure how to safely do that on Mac.

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jscher2000 said

The best way to isolate related errors is: (1) Open the Browser Console (2) Use the Console's clear button remove existing console messages (3) Load the Preferences page (4) Check the Console for any new messages related to the page load (5) On the Preferences page, click "Clear Now" (6) Check the Console for any new messages related to clearing cache

OK, I opened the Browser Console, and it said my "Tabzilla" is outdated, and gave a link to get a newer one, but at the site, I don't see where to do that, and what is "Tabzilla"?

Then I cleared everything, cleared my cache, and when I was finished, this is the only message created: TypeError: Type does not implements method: modelFor#1dv52p6m9co core.js:116:1

Any idea what that means?

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Tabzilla is a component of this site and perhaps other Mozilla sites. Not related to cache.

If you hover your mouse over the core.js link, is that an internal part of Firefox or a web link? Usually internal URLs start with resource:// or chrome:// and can indicate code of Firefox itself or an add-on.

If you click the link, Firefox should launch a viewer of the core.js file with the problematic line highlighted. However, I suspect that neither of us would know what it means... Still, you can copy/paste the address of the script file from the address bar so we can get an idea of whether it might be related.

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OK, here's the address of the script file:


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Thanks, that part of core.js seems to kick out error messages for script calls that try to use an unrecognized method. In this case, "modelFor" or "modelFor#1dv52p6m9co" was not recognized by Firefox for the relevant context.

When I search "modelFor", there are references to the Add-ons SDK, a component used in most newer extensions. Perhaps the cause is an issue with an extension that appeared in the console coincidentally with clearing the cache. The search also turns up references to Ember.js, which has a "modelFor" method used in web applications. Since you were on an internal Firefox page, this seems less likely to be the source of the error, unless a page in a different tab using Ember just happened to be executing some script at that moment.

Does that same error show up other times that you use the Clear Now button?

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Hi, jscher2000. Sorry to be so long in replying. I did the "about:cache" and here is the relevant information :

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  • IF* whatever is occupying that little bit of memory is something from third parties that has attached itself, would un-installing Firefox, then re-installing be likely to solve the problem?
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So the Preferences page reports a greater-than-zero value, while the about:cache page reports zero? Obviously one of those must be wrong, but I don't know what is causing the discrepancy or whether there is anything to be done about it.

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