Answer
If a new LU's sync fails in a way that doesn't map to an obvious cause, and the underlying view already existed with real data before the LU itself was created, check for a leftover/stale SVC package tied to that view — removing it and re-syncing has cleared up this exact class of confusing sync error, which is more likely tied to stale generated artifacts around the pre-existing view than a genuine problem with the new LU definition itself.