Unable to log into multiple Google accounts with Firefox

[ciacnorris]

@Aragorn

Animation speed in Plasma is adjustable.

Thanks but the issue is there only with some animations, while some work as usual. And my first description was wrong:

• Animations like Magic Lamp (for minimize and de-minimize) , Fall Into Pieces (for closing windows, I hope this is its right name in English) and Slide between virtual desktops go from making the global framerate and responsivity drop to being just a little slower than they used to be, and this behavior looks random.
• Animations like Wobbling Windows and the one you get when the window is resized work normally.

Another, totally different, issue: on Firefox, all of my Google accounts logged out and now I can log in only in one account. When I try to log in again into the second I get an error: “This browser or app may not be secure. Try using a different browser. If you’re already using a supported browser, you can refresh your screen and try again to sign in.” I have turned off both uBlock Origin and Firefox’s anti-tracking but I can’t get it to work.

EDIT: I have noticed that the slow animations problem seems to happen only when Firefox is involved. Everything else looks working as expected.

[scotty65]

@ciacnorris

on Firefox, all of my Google accounts logged out and now I can log in only in one account. When I try to log in again into the second I get an error: “This browser or app may not be secure. Try using a different browser. If you’re already using a supported browser, you can refresh your screen and try again to sign in.”

There was a change introduced in firefox v153 which could be causing the issue:

Firefox 153.0, See All New Features, Updates and Fixes:

Containers let you keep separate parts of your online life (work, shopping, personal, banking) logged into different accounts in the same browser window, but keep your cookies and ad tracking isolated inside each container.

You should also read through this:

How to use Firefox containers | Firefox Help

The Firefox Multi-Account Containers – Get this Extension for Firefox (en-US) may be required if you want to have multiple Google accounts logged in at the same time:

Note: Installing the Multi-Account Containers extension developed by Mozilla provides a few benefits on top of the native container functionality like site-specific container assignments, syncing across devices, and integration with Mozilla VPN or your own proxy. For more information, see the Multi-Account Containers article.

Multi-Account Containers | Firefox Help

If the above doesn’t get multiple Google accounts working, then the issue could be with Google.

[ciacnorris]

@scotty65

There was a change introduced in firefox v153 which could be causing the issue:

Firefox 153.0, See All New Features, Updates and Fixes:

Containers let you keep separate parts of your online life (work, shopping, personal, banking) logged into different accounts in the same browser window, but keep your cookies and ad tracking isolated inside each container.

You should also read through this:

How to use Firefox containers | Firefox Help

I read it but, unless I misunderstood something, it doesn’t explain why I can’t use multiple Google accounts at once like I used to do.
Before seeing your answer, I tried to add google.com to Firefox’s pop-up windows whitelist: it allowed me to log in into a second Google account, so now I’m logged into two of them, but when I tried the same procedure to log into a third account the error message appeared again.