This time I checked the SMSTS.log and found a new error

Quote

Content location request for WIN00018:3 failed. (Code 0x80040102)


followed by

Quote

Failed to resolve selected task sequence dependencies. Code(0x80040102)


SCCM OSD 0x80040102_第1张图片
I checked ConfigMgr and found that the package was the Windows Server 2008 Deploy Operating System Installation Package,
I checked that it had been distributed (it had) and updated (it had)
it still rebooted Windows PE, so I checked ConfigMgr's package status
loads of failed to access errors
SCCM OSD 0x80040102_第2张图片
workaround
delete the package and recreate it, then redistribute it, then verify that it's status in SCCM ConfigMGr (package status) is ok,
SCCM OSD 0x80040102_第3张图片
get it's package ID
SCCM OSD 0x80040102_第4张图片
then go back into Task Sequencer *it will alert you of the fact that it's missing anyway, as it's pointing to the old now deleted package ID*
SCCM OSD 0x80040102_第5张图片
and point it to the new Operating System Install Package
SCCM OSD 0x80040102_第6张图片
SCCM OSD 0x80040102_第7张图片