Came back from an errand earlier this morning and after turning on my Mac again, found that Thunderbird 115.10.1 was prompting me for my username and password at the web page for my account, using a pop-up Safari window. But trying to do that doesn't work because my version of macOS is not supported by Yahoo! Mail anymore. So I tried deleting the account and adding it back, since this is the very first time it's ever done this, but that doesn't work, either, because Thunderbird still prompts me for the same username and password using the same Safari window that won't work anymore. Tried updating Thunderbird to 115.16.3, but that makes no difference; still can't send or receive email. Who's idea was this, and why did nobody consider that web sites have dropped support for many older browsers that can't be upgraded, and give you no option to use a browser of your choice that would work for this, even though it should never be required? How do I (or others that are affected) solve this problem once and for all?