I think this came up once before (either here or on Reddit) and I don't recall there being an easy way to figure out what site it was from. How many cookies or how much storage space is shown for the site? Or is the row blank?

There are 3 cookies; storage space is blank. No indication of where the cookies came from.

I found a pending bug for this. More data is needed for investigation, so if you haven't cleared all cookies yet, they might be able to suggest a way to uncover the information.

https://bugzilla.mozilla.org/show_bug.cgi?id=1560865

I don't want to clear ALL cookies, so not sure what to do next.

Please don't clear all cookies. Hopefully the developers will suggest a way to figure out what the non-displayed site is.

First suggestion is to check for any error messages in the Browser Console when you try to "Save Changes" for the no-name site. Here's how:

(1) Call up the Manage Data dialog

(2) Pop open the Browser Console window using either:

• "3-bar" menu button > Web Developer > Browser Console
• (menu bar) Tools > Web Developer > Browser Console
• (Windows) Ctrl+Shift+j

(3) Click the trash can icon at the upper left of the Browser Console to clear the list of messages

(4) Switch back over to your main window and try the usual steps (select no-name site, Remove Selected, Save Changes)

(5) Switch back over to the console window. Did Firefox log any errors related to the attempted deletion?

More info on the Browser Console: https://developer.mozilla.org/docs/Tools/Browser_Console

One possible source of a no-name cookie would be a cookie set by a local file (page opened on a file:/// URL). A bug is on file for that: https://bugzilla.mozilla.org/show_bug.cgi?id=1565998

If your undeletable cookie was set by a file you opened locally, I don't know whether that makes you feel any more or less comfortable!

Browser Console comes up with:

Discarding onCreatedNavigationTarget for 17: received source tab data without any created tab data available XHRGEThttp://detectportal.firefox.com/success.txt [HTTP/1.1 200 OK 16ms]

Discarding onCreatedNavigationTarget for 17: received source tab data without any created tab data available Stylesheets without CSSOM changes reparsed to check for errors. Refresh the page to also see errors from stylesheets changed from CSSOM and from style attributes. 4 stylesheets actor: fetch failed for chrome://browser/content/preferences/siteDataSettings.css, using system principal instead. stylesheets.js:219:13 Stylesheets without CSSOM changes reparsed to check for errors. Refresh the page to also see errors from stylesheets changed from CSSOM and from style attributes. 2 Unknown property 'user-select'. Declaration dropped. reps.css:23:15 Stylesheets without CSSOM changes reparsed to check for errors. Refresh the page to also see errors from stylesheets changed from CSSOM and from style attributes. Error: Failed to fetch chrome://browser/content/preferences/siteDataSettings.css. Code 2152857618. DevToolsUtils.js:544:16

Does that help?

More from Browser Console:

GEThttps://d2bnxibecyz4h5.cloudfront.net/runtimejs/intercept/intercept.js [HTTP/1.1 200 OK 16ms]

GEThttps://static-media-prod-cdn.itsre-sumo.mozilla.net/static/sumo/img/apple-touch-icon.png [HTTP/2.0 200 OK 16ms]

GEThttps://static-media-prod-cdn.itsre-sumo.mozilla.net/static/sumo/img/favicon-16x16.png [HTTP/2.0 200 OK 16ms]

XHRGEThttps://surveygizmobeacon.s3.amazonaws.com/beaconconfigs/MjgwNDktQUYyRDQ3ODk0MjY1NEVFNUIwNTI3MjhFMDk2QTE3RDU%3D.json [HTTP/1.1 200 OK 266ms]

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://location.services.mozilla.com/v1/country?key=fa6d7fc9-e091-4be1-b6c1-5ada5815ae9d. (Reason: missing token 'x-csrftoken' in CORS header 'Access-Control-Allow-Headers' from CORS preflight channel).

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at https://location.services.mozilla.com/v1/country?key=fa6d7fc9-e091-4be1-b6c1-5ada5815ae9d. (Reason: CORS request did not succeed).

Error: Error retrieving geoip data common-min.5594359fa3da.js:10:27783 Request to access cookie or storage on “https://static-media-prod-cdn.itsre-sumo.mozilla.net/static/sumo/img/apple-touch-icon.png” was blocked because we are blocking all third-party storage access requests and content blocking is enabled. 1264791 Request to access cookie or storage on “https://static-media-prod-cdn.itsre-sumo.mozilla.net/static/sumo/img/favicon-16x16.png” was blocked because we are blocking all third-party storage access requests and content blocking is enabled. 1264791 Request to access cookie or storage on “https://d2bnxibecyz4h5.cloudfront.net/runtimejs/intercept/intercept.js” was blocked because we are blocking all third-party storage access requests and content blocking is enabled. 1264791

Thanks for that.

This one seems to occur any time I pop up the Save Changes window:

Discarding onCreatedNavigationTarget for [number]: received source tab data without any created tab data available

Then reviewing what comes after that, it seems to be mostly errors with style rules. I don't see any saying why the action didn't work. I'll pass it along.

The requests in the second group look to be related to some tab other than the Options/Preferences page.