Two scenarios possible: • the prefs.js file in your Thunderbird profil got damaged, was renamed in prefs-1.js and replaced by a new virgin prefs.js file which doesn't contain any account information or... • Thunderbird for un unknown reason created a new virgin profile (an issue which I've never encountered myself nor seen in any forum) I presume that after your update Thunderbird opened displaying a start page in which you were prompted to "set up your existing email address" (see image) Probably you set up new accounts for your email addresses, but why did you set them up as POP accounts since you had been using IMAP accounts ?

Now in Thunderbird (TB) go to Help> Troubleshooting information > Profile folder > Open Folder, then close TB. In the profile folder xxxxxxxx.default-release (or similar) look for a prefs.js file and note its size. Also look for any prefs-x.js file and note its date and size. From the profile folder navigate one level higher to the folder "Profiles" and make a screen shot of its contents.

Hi Mapenzi, Thanks for helping. Yes that's the screen I got after the update, not sure what I did but obviously set it up wrong. There was no prefs-x.js file. Hope it helps, I'm a bout of a novice with this. Thanks again Wayne

Thank you for the helpful screen shots. Obviously Thunderbird didn't create a new profile but is still using the "xxxxxxxx.default-release" profile. I'd asked you to look for a prefs-x.js file (x being a number such as 1, 2 , 3 ... etc) which in fact is absent. Yet I forgot to tell you that Thunderbird sometimes renames a presumably corrupt prefs.js file to invalidprefs.js, and such a file from 01/04/2026 is clearly visible at the top of your image showing the contents of your profile folder. This confirms the diagnosis of a probably damaged and renamed prefs.js file.

It can also happen that Thunderbird renames even a healthy prefs.js file, at the same time creating a new virgin prefs.js file. So let's first try the following manoeuvre : open the profile folder again as indicated in my first answer, close Thunderbird, move the actual prefs.js file from April 3rd to some other directory (e.g. Desktop), rename the invalidprefs.js file back to prefs.js and start Thunderbird again. Report whether your accounts, folders and messages are displayed as they used to be before you updated on April 1st.

Thanks Mapenzi problem sloved. I really appreciate your help in this. Everything is back to normal.

Everything is back to normal.

Thanks for your instant feedback! I'm glad I could help you.