Migration from Teamviewer Manager 10 to Management Console fails


We've been using Teamviewer version 12 with the Teamviewer Manager v10.0.1060 so far.

Now we've updated Teamviewer to version 13 and want to use the content of our old Teamviewer Manager in the Teamviewer Management Console, but when we use the "Data Migration Tool" supplied by Teamviewer we get an error "Database has errors".

Our Database is okay so far, and I also checked the Database file with sqlite, and it has shown no errors.

This is what the log of the Migration tools shows us:
[15.10.2018 14:45:30]    ManagerDataConverter started     Microsoft Windows NT 6.1.7601 Service Pack 1    MigrationTool
[15.10.2018 14:46:00]    Setting up SQLite Connection - C:\TMP\tvmanager.db
[15.10.2018 14:46:00]    Start Import
[15.10.2018 14:46:00]    --- Import started: 15.10.2018 14:46:00
[15.10.2018 14:46:00]    --- Import Failed: Database has errors.
[15.10.2018 14:46:03]    Finish
[15.10.2018 14:46:03]    Shutting down Gui

Has anyone an idea how we can fix this?