When trying to migrate an OS deployment task from SCCM 2007 to SCCM 2012 R2, I receive the error "Failed to insert OSD binaries into the WIM file" during the step that copies the boot image. I have confirmed that the SCCM 2012 server has access to the required files.
The hard part here is that the SCCM migration log doesn't give you any more detail than the SCCM UI. However, the WIM image is mounted to insert the drivers and DISM is used to service the image.
Consult the DISM log at