How do I go back to the old version of Yahoo Mail - the one that was in use in spring 2019?

Go to setting on the right. Click on "more setting" on the bottom. Look to the left and click on "switch to basic mail."

Hope that helps.

Uninstall your updates only if it's ......

You can't they have phased it out to bring you the "new and improved" version that you don't like, that no one likes.

i'm beginning to realizes there's no reason to use yahoo/anything mail or any products they have. comments are censored for no reason other than someone abuses the report button because they disagree with your opinion on any subject you comment on. either yahoo with their unbelievable liberal views or some sjw buttwipe views reporting abused just because they disagree. yahoo, you should look at this, and stop the abuse of this flash flagging. and give us the chance to go back to the old yahoo mail, i despises the new yahoo mail.

you are not yahoo is out with the old , in with the new, do not like it ? move to gmail, fast easy to use

i dont think you can, i think its gone for good

It's no longer possible to switch back to the classic version of Yahoo Mail. It has been discontinued. There are currently 2 versions of Yahoo Mail for desktop web browsers that you can use: Basic Mail and the full-featured Yahoo Mail: https://help.yahoo.com/kb/sln15936.html