Again: Does anyone know if it is possible to delete the downloaded blockchain, re-trigger downloading it from start without lossing account date or blackbytes? Please tell me, I'm having heavy problems with the client.
I believe the Byteballs are stored in the DAG, so don't delete it.
Can you try this so that you don't lose anything:
Back up the entire user folder where all of the Byteball files are kept including the DAG,(should be over 1 gig)
Ensure it's all backed up / moved.
Now you can safely delete the files and restart, see what happens.
If you Blackbytes don't return then you have neutral news and bad news.
Bad news is that you're going to have to reload your backup.
Neutral news is that you have not lost anything.