Do you mean you want to take Office out of the container -- which I think is necessary because otherwise you need to add a half dozen other Microsoft domains?

Assuming you use the Multi-Account Containers add-on, click its toolbar button and then find the container it is in. Carefully click the number or > on the right side of the container name to open the sites list. When you hover any site, an X button should appear to remove it from the container. This might close any tab open to that site.

Does that work on yours?

I think something needs to be added to the support article "Multi-Account Containers" about this.

Okay, wait, that didn't work. The next time I try the address I get this:

There must be some secret I'm not aware of (I'm testing, not a regular user).

jsher2000. Your 2nd response is exactly the issue I'm experiencing! I don't see a way to remove my request from the container. From a User standpoint, I typically open office in multipe containers (for example, O365 for work, for school, for personal).

Maybe check this issue:

• https://github.com/mozilla/multi-account-containers/issues/2257

I checked out the link provided by cor-el: https://github.com/mozilla/multi-account-containers/issues/2257

I am still confused, I see comments stating that once you have chosen always open in X container you can't undo it? Am I missing something?

BTW - Thanks to all for your feedback and assistance w/ this. It is having a very negative impact on my ability to access different O365 accounts.

I followed a few links on Github until I found the secret: it is on the page context menu. You might think it would be on the tab context menu, the menu that opens from the address bar icon, the menu that opens from the toolbar button, but no...

What I'm trying to accomplish is to "forgtet" the container. This isn't an option? Refer to screen shot. You can see the container I'm in is called Cook M&A.

There probably is a way to delete the container, but I haven't looked for that yet. If you close that container tab and open a regular new tab and navigate to Office, does it open normally now?

If I close container and try in open in a normal Firefox tab it defaults to the Container tab and that's when I experience the endless loop (I can't log into office). My work around is to use a Firefox private window...this is fine for short term solution but not long term.

Hmm, in my test with Google, the site was removed from the container after I "un-checked" Always Open in This Container. I can see the change when I use the add-on debugging Storage tab, Extension category. (Screenshots attached for reference.)

The next time I opened the site, there was no message about whether to use a container.

I have played with using a little bit of script to remove a site, but I can't be sure of its safety, it might affect other sites/containers. If it would be easy to rebuild your container list, this is the idea:

(1) Open the about:debugging (type or paste that into the address bar and press Enter to load it)

(2) In the left column, click This Firefox to show your running extensions

(3) Click the "Inspect" button for Multi-Account Containers

(4) Click the "Storage tab" and expand "Extension Storage" and click the extension entry under that heading

(5) Expand the "Key" column by clicking and dragging the divider after the word Key -- this will allow you to confirm how Office is listed (i.e., www.office.com or some variation)

For example, if Office appears in a key named siteContainerMap@@_www.office.com then you'll use www.office.com in the hostname in step 7.

(6) Click over to the Console tab and paste this template in the entry area :

// Customize to your key
var hostname = 'www.office.com';
var port = '';
// No need to customize this part
var key = 'siteContainerMap@@_' + hostname + port;
browser.storage.local.remove([key]);

(7) Customize the hostname and port if needed to match the key saved by Multi-Account Containers

(8) Execute the script -- look for a run button above the script (in the two-column layout) or press Enter to submit the script (in the one-column layout)

The script displays that a promise is pending. That's correct.

To test the results, try opening Office in a new tab

Note that you can use 'await' to allow the promise to finish properly.

await browser.storage.local.remove([key]);

I ended up deleting all of my existing Containers and then removing the add-in from my browser. Upon recreating the containers in new browser session, the issue went away and I'm now able to log into multiple Office 365 accounts in multiple containers w/ no issues. Thanks all for your help! Firefox multi account containers is a great feature!!!!