Hi UEMdev,
thank you! This helps alot. You was right, UAC was disabled. The reason was that we using the VMware Customization Tool and the VMWare official Windows 10 template. There was a setting which disabling the UAC. Ive now modified the template and do a reinstall of the gold image. If its finished i will let you know if this was reason for the error 5.
Thanks!
best regards
Alex