My Dad's Portable thunderbird keeps deleting accounts. It happend second time today. Maybe it's because the device lost power when using Thunderbird. At the first time, which was a few months ago, I didn't find any good solution for this -> I created accounts again, and packed old emails into local folder. But now I started to think if there is any solution to get rid of crashes like that? For me it wouldn't be a problem but it's my dad's flash drive with his work correspondence... Can I restore the old accounts or I really need to create them again and move mail files manually? I started to think this is not a good app solution for him... Cheers!
EDIT: when I tried to see verision of TB it shows 68.12.0 and started an update.
EDIT2: Ok so I've created a new clean account and thunderbird automaticaly download "new" e-mails (pop3). They start in may this year and end today. But I have another inbox folder where are another emails received in last months (including may-september), and another one (third) inbox folder where are emails up to 2019. I wan't every of this three inbox folders to merge into one. Is it possible or do I need to create different local folders in Thunderbird like "old", "new", "newest"?