Error 338 means that the GhConfig.EXE tool which applies the configuration part of a task has encountered a SYSPREP.INF file in the image, but it is not able to understand the layout of the file well enough to edit it.
Prior to GSS2, people who tried to use Sysprep with GSS would often complain about losing configuration settings; this is because our tools adjusted the machine configuration before sysprep ran, and sysprep would undo whatever we did.
So, now our tools try and edit the sysprep.inf file to reapply the same settings. However, editing the sysprep file in-place means understanding what's in it, and some hand-constructed sysprep files have unusual layouts that our code to read the file doesn't understand. To fix these, will need to see the
exact contents of the INF file being used.