Troubleshoot Mode runs Thunderbird with some features and customizations disabled (see below for details), does not affect your data, and changes are temporary unless you choose to make them permanent. If you are having a problem in Thunderbird that does not occur in Troubleshoot Mode, then the cause of the problem is one of the disabled items.
Table of Contents
Starting Thunderbird in Troubleshoot Mode
- Switch to Troubleshoot Mode:
- If Thunderbird is not running: Hold down the Shift key while starting Thunderbird.Hold down the option key while starting Thunderbird.From Terminal, run this command:
thunderbird -safe-mode
You may need to specify the Thunderbird installation path (e.g. /usr/lib/thunderbird or ~/Downloads/thunderbird/thunderbird). - If Thunderbird is already running: Click > > and in the Restart in Troubleshoot Mode prompt, choose .
- If Thunderbird is not running: Hold down the Shift key while starting Thunderbird.Hold down the option key while starting Thunderbird.From Terminal, run this command:
- In the Thunderbird Troubleshoot Mode dialog, click button.
- If you want Troubleshoot Mode changes to be temporary, do not check the checkboxes - temporary is the default. But you can choose to make the changes permanent.
- Click > and check if you see in the menu, to confirm that Thunderbird is currently running in Troubleshoot Mode.
Turning Troubleshoot Mode off
Click > > to immediately close Thunderbird and restart it in normal mode.
Or you can just exit Thunderbird and start as you normally would.
Diagnosing problems in Troubleshoot Mode
After you start Thunderbird in Troubleshoot Mode, test its behavior to see if the problem goes away.
The problem still happens in Troubleshoot Mode
If the problem still happens in Troubleshoot Mode, it is not being caused by an extension or theme installed in Thunderbird. Possible causes and solutions include:
- Something wrong with your Thunderbird installation: Reinstall Thunderbird from https://www.thunderbird.net/.
- Something is wrong with your Thunderbird installation: If you had installed Thunderbird using the Linux package manager, try reinstalling it. Also investigate possible library conflicts, and consider using the Thunderbird supplied package from https://www.thunderbird.net/.
- Something wrong with your operating system: Start Windows in safe mode.
- Changes made to Thunderbird preference settings not disabled in Troubleshoot Mode.
The problem no longer happens in Troubleshoot Mode
If the problem no longer happens in Troubleshoot Mode, the most likely cause is an extension, theme or hardware acceleration. Possible solutions include switching back to normal mode, then doing the following. (You may need to restart Thunderbird after each step to see if it solves the problem.)
- Progressively disable extensions in the add-ons manager: Click > > , then check if the problem remains after disabling each extension. When the problem goes away, the last disabled extension is probably the trouble causer. You can try to update it, reinstall it, leave it disabled, or remove it.
- Set the default theme in the add-ons manager: Click > > , then enable the default theme.
- Try turning off hardware acceleration in Thunderbird's settings: Click > > , then uncheck .
What does Troubleshoot Mode disable?
- Add-ons (extensions and themes)
- Hardware acceleration
- Window and sidebar size and position settings (described in terms of Firefox)
- userChrome and userContent customizations
- JavaScript Just-in-time (JIT) compiler
