"I cannot hire a worker into this legal employer." Check in this order. One: is the legal entity actually designated as a legal employer? Two: is there a business unit associated with it? Three: is there an LDG, and is it associated with the PSU? Four: does the legal address validate? Five: is the employment model set, at enterprise or legal employer level? Six: does your security allow you to see that legal employer?
Then seven failures. The business unit list is empty at hire — no association between the legal employer and the business unit. A one-minute fix and half a day to find, because the symptom looks like a data problem and the cause is structural three tasks away. Two countries share an LDG and payroll cannot be configured — the design error from the LDG lesson. No practical fix. Full re-model. This is the one the whole module exists to prevent.
Workers were hired into the wrong legal employer — corrected only by termination and rehire, with the service date consequences. Prevention: verify the structure with a test hire before any real load, which takes ten minutes. The payroll team says the TRU structure will not support their statutory rates — PSU and TRU designed without asking about deduction levels, and expensive to correct after workers exist. Legal entity creation fails on the address — the geography hierarchy is incomplete for that country. We added a fourth country and nothing works — a new country needs its own jurisdiction, legal entity, employer designation, PSU, TRU and LDG: adding a country is a sequence, not a checkbox. Grades from country A are appearing in country B — reference data set assignment.
And the close. Four of those seven trace back to decisions made in the first six lessons of this module — at zero cost, before anything was built, in a room with a whiteboard. That is this module's entire argument, and it is why the design half is longer than the build half.