Hello @marcus.sohl,
Welcome to the LastPass Community!
I apologize for the inconvenience this is causing you. I will suggest trying to make the export from the web vault directly. You just need to login and under advanced options you will see the option export.Then once you approve the verification email about the export you can complete the export process from the same place or the extension by following these steps:https://support.lastpass.com/s/document-item?language=en_US&bundleId=lastpass&topicId=LastPass/export-generic-csv.html&_LANG=enus
Kind Regards,
Alejandra
LastPass Tech Support