Hello!
Thanks for the answers! I needed some time because I'm sick. I would like to briefly respond to your answers:
1. I use Electrum not under Windows but under Ubuntu.
2. The wallets are ok. My electrum has a little bug. It can not be stopped and continues in the background. That's why I was unable to see any transactions when I restarted. This was blocked in the background.
3. I have exported my private key after the youtube manual
https://www.youtube.com/watch?v=LaijbTcxsv8. The key can not be imported into Electrum. There are several keys in the exported file. One per line. No key can be imported. The Next button in the "Create keystore from a master key"-window does not become active. I can not get any further at this point. Where could the problem be?
4. I signed in to
https://pool.viabtc.com to use the "Transaction Accelerator". The free pool of 100 TXIDs is unfortunately always occupied immediately. For the paid service, I would have to deposit something first. Of course this does not work anymore with my Multibit and at Electrum my credit is not yet available. That's a vicious circle.
Meanwhile, I no longer see the forest in front of trees. What can I do above all in point 3 that the import of the keys works in Electrum?
Best regards
Alex!