If one of your old passwords works with webmail, note which one it is and use that with certainty in Thunderbird. Also, try a new Thunderbird profile. See Profile Manager - Create and remove Thunderbird profiles

The one profile I could not delete was said to be in use, but wasn't. Tried re- downloading but get the same issue with passwords.

Un installed and tried a new download without any set up and it opens with my default profile. Tried to locate the file (copy & paste into file explorer) from about:profiles but it is not shown!

Using the steps in the Profile Manager article I linked to in my previous reply, create a new profile and launch it. Uninstalling and reinstalling Thunderbird normally does NOT remove the existing profile(s). You don't need to remove the existing profile so as to create and launch a new one. The newly created profile will launch in its own window (instance) of Thunderbird.

As I only have one email address (is that my "profile") surely I can't create another with it, or it would be the same as previously used?

No, your email address (account) is NOT your Thundebird profile. See Profiles - Where Thunderbird stores your messages and other user data for a detailed explanation of what a profile is. I believe every Thunderbird user needs to know all they can about profiles. When you've finally understood what a profile is, head over to Profile Manager - Create and remove Thunderbird profiles and use the information there to create a new profile and launch it. The idea is to start with a fresh new profile and see if you can successfully setup your email account on that new profile using the password that has been confirmed to be working on webmail. A lot of times, issues users face with Thunderbird are a result of their profiles getting messed up or corrupted in some way, and starting afresh with a new profile is, in my opinion, the most effective approach in the long run, and also a good troubleshooting step to ascertain if the problem lies within a certain profile or elsewhere.

Hello Stans, thank you much clearer now. Started by changing email provider password, logs into my mail. Logged out. Found my profile saved files and deleted. Opened a downloaded Thunderbird and without setting a profile manually entered data, new password, server connections. Copied password from the configuration page of Thunderbird, pasted into web mail and it logged in, Thunderbird had found connection data but then the repeat of the error message "unable to login at server. Probably wrong configuration user name or password. Looked in %APPDATA%\Thunderbird\Profiles\ found new profile name. What am i doing wrong?

According to https://www.virginmedia.com/help/broadband/manage-email-account and https://www.virginmedia.com/help/billing-and-payments/login-problems you need an app password for use with Thunderbird. The app password is NOT the same as the one you use to sign in to your account via webmail.

Yet here it says not so:_ "Virginmedia.com supports IMAP / SMTP This means you don't have to use Virginmedia.com's webmail interface! You can check your email and send messages using other email programs (like Mailspring, Outlook Express, Apple Mail, or Mozilla Thunderbird). Using desktop email applications can improve your workflow." Also found an answer to an earlier exact issue, apparently solved by giving Thunderbird the VMedia password.

Stans, you are entirely right. It's those B.......s at Virgin Media. They have apparently only recently required 3rd part apps users to sign in with a password generated my themselves. MyVM > Account Settings > Account details > Mailbox App password management

Thank you for all your help and to Graham, (lost the link to him) Graham_A

Very Insightful Person Graham_A

Very Insightful Person yesterday

VM have recently changed the log in requirements for accessing VM Mail via third party apps.

If you change the password for the account in My Virgin Media > Account settings > Account details you will not be able to use the new password to access the account via an email client. Email client access now requires an app specific password which can be generated in the MyVM > Account Settings > Account details > Mailbox App password management

@daleman9