WHat happens if you do Help > Troubleshoot mode in both?

Thanks Wayne, but clicking on Help does nothing - I get no drop-down so I can't select Troubleshoot in both!

Try instructions for starting TB in safe mode https://support.mozilla.org/en-US/kb/troubleshoot-mode-thunderbird?redirectslug=safe-mode-thunderbird&redirectlocale=en-US#w_starting-thunderbird-in-troubleshoot-mode

I have tried that - and I have now tried again, but it makes no difference - drop-downs still do nothing!

just a wild guess, but change the setting for hardware acceleration in preferences. (Probably turn it off as the developers saw fit to force enable it again)

Thanks Matt - sorry to be a bit dumb, but which settings are you referring to? Bear in mind I can't get at the Thunderbird drop-down menu on the top right.

Assuming your profile is stored in default location.

Exit Thunderbird this is important.

Linux and Unix Profile folders are located here:

   ~/.thunderbird/<Profile name>/ 

However, if you're using a third party build from Debian or Ubuntu, those builds store your profile folder here:

   ~/.mozilla-thunderbird/<Profile name>. 

In 'profile name folder which typically is xxxxxxxx.default or xxxxxxxx.default-release where the x's are letters and numbers.

In the 'profile name' folder look for these files and delete them.

• session.json
• xulstore.json

then start Thunderbird and report back on results.

Many thanks Mr Toad! I've carried out what you suggest, but it makes no difference, I'm afraid.

Alyn

Thanks Matt - sorry to be a bit dumb, but which settings are you referring to? Bear in mind I can't get at the Thunderbird drop-down menu on the top right.

Use the keyboard. Seriously. And the real menu system, not the HTML one that the app menu button creates.

Pressing f10 will make it visible it it is not and I think your drown menus will probably work there.

See if the old method works.... Do you have the 'Menu Bar' toolbar showing across the top of window ? It has 'File, Edit, View etc... If no: Press 'Alt' key to get to display. Then immediately use 'View' (Alt+V) > (then use arrow keys to move highlight) 'Toolbars' > select 'Menu Bar' - press enter.

Then use keyboard again... 'Tools' > 'Preferences' Use 'Alt+T' to select 'Tools' and then just press 'P' to select 'Preferences' which opens in a new tab. It should auto open on 'General' - or select in left pane. Scroll to bottom. do not select - uncheck if necessary 'Use hardware acceleration when available'

Exit and then restart Thunderbird.

I have the Menu Bar toolbar, and can use Alt+T to highlight the Tools item, but pressing P has absolutely no effect.

I have in the meantime uninstalled both firefox and thunderbird, removed .mozilla & .thunderbird directories, and re-installed both apps, but made no difference.

I have the Menu Bar toolbar, and can use Alt+T to highlight the Tools item, but pressing P has absolutely no effect.

TRy: use Alt+T to highlight the Tools item and then use arrow keys to move down to 'Preferences' and then click on 'Enter'

It should open 'Preferences' in a new tab

Alt+T highlights Tools, but down arrow has no effect!

I can highlight Tools just with the mouse, but no drop-downs whatever I do, it seems!

Just an extra note - it I have an email that contains pictures etc and I'm asked if I want to display them, then clicking on "Preferences" also has no effect.