[Bug] Firefox Creating Cache2.Purge.BG_RM-CachePurge Files When Set to Clear Cache on Close

Today in this article, we are going to discuss about a weird bug present in popular Mozilla Firefox web browser which appeared after release of recent Firefox 109 version. This bug causes Firefox to keep creating random “cache2.2023-xx.purge.bg_rm-cachePurge-xx” files in its ProgramData folder if “Clear history when Firefox closes” option is enabled in Firefox Settings as shown in following screenshot:

Yesterday, our reader “Jack Smith” shared interesting information about this annoying Firefox bug. Here is the reader’s comment posted at our Help & Support page:

I searched on Internet to find whether other people are also facing similar issue. I noticed the same comment was posted by a reader “E” at gHacks website. I don’t know whether both Jack Smith and E are same person or not but since the comment posted at gHacks was old, I though of sharing it as a reference.

Many people here know that I also use Firefox as primary browser on my devices. So I immediately checked the mentioned folder in my Windows 11 device but I didn’t find those “cache2.xx” files there.

The “C:\ProgramData\Mozilla-1de4eec8-1241-4177-a864-e594e8d1fb38” folder was containing a single “updates” folder and following 4 files:

• profile_count_308046B0AF4A39CB.json
• uninstall_ping_D78BF5DD33499EC2_1b11f0ea-d6a0-4fd5-bc2b-f261480feb11.json
• UpdateLock-308046B0AF4A39CB
• UpdateLock-D78BF5DD33499EC2

Then I enabled the clear cache option which the reader shared in his comment. Here is how I enabled the option:

1. Open Firefox Settings (about:preferences) page.

2. Click on “Privacy & Security” section in left-side pane.

3. In right-side pane, scroll down to History section and enable “Clear history when Firefox closes” option.

PS: The same clear history when Firefox closes option can be enabled using about:config page. Just set privacy.sanitize.sanitizeOnShutdown preference/flag to True.

4. Again click on “Settings” button given next to the clear history option and enable “Cache” option only as shown in following screenshot:

After enabling the option, I closed Firefox and I checked the “C:\ProgramData\Mozilla-1de4eec8-1241-4177-a864-e594e8d1fb38” folder again. I was surprised to see a new file “Cache2.2023-xx.purge.bg_rm-cachePurge-308046B0AF4A39CB” created in the folder. The file size was 0 bytes and Windows was unable to detect its file type. Windows was showing it as an unknown “.bg_rm-cachePurge-308046B0AF4A39CB file” as the extension was automatically taken from the file name.

So it’s definitely a bug in latest Firefox version which creates tons of cache2.xx files in Firefox’s ProgramData folder when clear cache on shutdown option is enabled.

Unfortunately, the bug still exists in the latest Firefox 109.0.1 version.

Now what can be done to fix this bug?

If you don’t use “Clear history when Firefox closes” feature and the option is disabled in your Firefox browser, you don’t need to worry about the issue. Firefox will NOT create any random cache2.xx file in your computer.

But if you have enabled the “Clear history when Firefox closes” option, you can uncheck or deselect “Cache” option to fix the issue temporarily. If you enable other History options, it’ll not cause any bug. It’s the only “Cache” option which is causing this bug in Firefox. If you disable the whole “Clear history when Firefox closes” option, it’ll be the best decision for the moment.

Fortunately, the cache2.xx files can be deleted safely without any issue. So you can delete those files whenever they are created by Firefox. The files are only created when you close or restart Firefox browser.

We should hope Mozilla team will fix the bug soon in upcoming Firefox releases.

Thanks to our reader “Jack Smith” for letting us know about this bug…

Also Check:

[Fix] Firefox Showing Blank Unknown File Icon in Windows Taskbar