There are a number of files in the profile folder that affect the layout, and by deleting or renaming them, TB will automatically create new, uncorrupted versions. Select Help/Troubleshooting Information, click Open Folder to open the profile folder in Explorer, then close TB. Delete or rename these files: xulstore.json, session.json, foldertree.json and directoryTree.json. Restart TB and see if the folder pane retains its expanded/collapsed state.

http://kb.mozillazine.org/Toolbar_or_windows_layout_not_working

Hi - Thanks for your answer, I deleted the folders but unfortunately I still have the problem.

I tried deleting them a few times and restarting thunderbird after each time I deleted them but no joy.

Any other ideas? Thanks

Do you have any kind of program like CCleaner working in the background and possibly resetting TB settings between restarts?

Hi - CCleaner was set to clean 5 items in Thunderbird - Internet Cache and History, Cookies, Download History and Last Download Location. I have unchecked all the boxes and i then did a few restarts but I still have the problem. Many Thanks for your help

The only other file that can be deleted and automatically recreated, that contains folder settings (that I can think of), is panacea.dat. Delete or rename it and see if the folder state is retained.

If that doesn't work, you could create a new profile with Profile Manager, add an account, and see if the new profile behaves properly. If it does, the data from the old profile can be transferred to the new one.

To start Profile Manager, close TB, select Windowskey+R, type: thunderbird.exe -p

Hi - Deleting the file did not work, I will try the profile manager option and let you know how I get on. Many Thanks

Hi - I think my problem is now solved. Many many thanks for your help.

conrod said

Hi - I think my problem is now solved. Many many thanks for your help.

and the cure was? It is always good to leave a solution for the person whop searches on similar issues.

After I deleted the file it did not work, but then yesterday morning it started working so i did not try the profile manager option as i thought the solution had been found. But this morning the problem has reappeared so I will have to try the profile manager option, I will let you know how i get on. Thanks

Hi - Tried new profile option but I could not get Thunderbird to accept settings for email on the account I tried (I am with talktalk). I use POP3 for my email, I have had problems in the past with talktalk email! I think I am going to leave everything as it is and just put up with restarting Thunderbird every time my computer is restarted to give me the email account view I want. Many Thanks for your help. PS - Just restarted my computer and email view is how I want it! It will probably change again on next restart, who knows! I am going to lie down in a dark room!