1. Check your computer Graphics driver is up to date.

• Exit Thunderbird.
• Update the Graphics driver.
• Start Thunderbird.

If you still see a problem: 2. Switch off hardware acceleration.

• Settings > General
• Scroll to bottom and uncheck 'Use hardware acceleration when available'

Thank you for your quick response. Unfortunately neither of those suggestions worked. I have uninstalled and reinstalled several times to no avail. Also I change the layout and next time I open Thunderbird it has deleted my selection. These problems only started with the last couple of updates. Never had a problem before. Do you have any other suggestions to help as I don't want to change from Thunderbird if I can help it. John. PS>>>> I was hoping to attach a video to this but it will only allow a photo

In 'Addons & Themes'

What 'Theme' are you using - 'Dark' or 'Light' or 'System Theme' ?

In 'Extensions' - what addon extensions have you installed ?

re: Also I change the layout and next time I open Thunderbird it has deleted my selection.

That sounds like either something is not getting updated or something is deleting session files so they cannot update files on exit. In the past I've come across products like CCleaner which clean up files and they can cause havoc.

1. Do not allow any Anti-Virus or malware type of product or any thing like CCleaner or WiseCleaner to have access to your thunderbird profile folders. Please Exit Thunderbird and then access those type of products and make Thunderbird an exemption not to scan that folder or anything it contains. Your 'Thunderbird' profile folder is located here - assuming you are using Windows OS and profile is in default location.

• C://Users/User name/Appdata/Roaming/Thunderbird

If you did have those products scanning etc then maybe it will fix the loss of session and updating of files.

2. However in addition you can safely do the following just in case you have some corrupted files. It recreates them upon restart.

In Thunderbird

• Help > Troubleshooting Information
• Under 'Application Basics' - half way -Profile Folder - click on 'Open Folder'

It will open in a new window showing you the contents of your profile name folder.

• Exit Thunderbird now.

Delete the following files:

• global-messages-db.sqlite
• session.json
• xulstore.json

Start Thunderbird.