- an Unattended.xml file is used with the "Apply Operating System" Task sequence step
- The "Apply DriverPackage" step exists in the TS and is not disabled.
To resolve this isssue you could, before you start TS Export, remove the XML file from the "Apply Operating System" step, disable the "Apply Driver Package" step, or apply the lates Hotfix/CU2 (KB3100144)