When I see 'Failed to run Task Sequence - This task sequence cannot be run because the program files for XXXXXXX cannot be locataed on a distribution point'

I go to Monitoring \ Distribution Status \ Content Status. It's the quickest way to search all package objects. Today the search came up with no results.

I exported the task sequence to make sense of it, found the ID in a section about OSDSubTaskSequenceTsReferencePackages -

<variable name="OSDSubTasksequenceTsReferenceApplications" property="TsReferenceApplications"></variable>

<variable name="OSDSubTasksequenceTsReferencePackages" property="TsReferencePackages">ZZZ00019,ZZZ0001F,ZZZ00020,ZZZ00024</variable></defaultVarList></subtasksequence>

What happened was someone removed a driver package and deleted it. The main task sequence still referenced it. To fix I modified the main task sequence, so it kicked off new policies.