Yahoo authentication fails on password update

Am trying to save others the time I’ve wasted on this one - after changing a Yahoo account password, emClient failed to authenticate, with the dreaded ‘Uh ho’ error.

I found this post (FIXED! Yahoo Accounts and eM Client) that seemed to cover the issue, but as it was two years old and as my (v7) client was up-to-date (according to the update facility) I ignored it.

Wrong, in two ways! Firstly, although the problem occured two years ago, it only manifests itself on a new authentication action - in my case when the yahoo password was changed. Secondly the emclient update tool failed to alert that the version identified in the post referenced above, was not loaded (or that subsequent versions did not not include the changes.). Of course v8 and v9 embrace the yahoo changes, but those who lumber on with v7, might still be caught out!!

As it is the New Year, you have my permission to troll me not.
Ron