Out of nothing, after simple opening of Bat, there are just the basic folders: Inbox, Outbox,Sent, Trash (two hours ago there were all of them). All the other folders which have been here all the time, with lot of messages, are not here any more (!!!). Simply disappeared
I am a bit shocked ... That´s already too much ...

I don´t know what to do ... so many important messages were there. I have some backup, but from few days ago ..

Also the folder columns (parked, flagged etc.) are reset somehow ...

I already lost lot of messages few times with Bat ("corrupted folder"). But this is a massive thing.
I have to consider this programme as highly unreliable and betraying ... sorry ... something like this never happened to me in any other mail client I have used before

EDIT: I just looked in the Bat folder in the appllication data: these folders are still there (with full volume of messages).

How to get them back to the programme ??