We regret this confusion. That request is general and not directed at any one person. Thunderbird on your computer is not aware of whether you donate or not. We request your tolerance. Thank you for your donations. It is the minority of users who contribute and it is those who are keeping Thunderbird alive and growing. Again, thank you for your support.

Thank you for your prompt reply! However, my problem is how do I clear it and restore my Thunderbird page!

Try unticking the 'thunderbird start page' under settings>general