X_VECTOR_DIM_MISMATCH
Means
embedding dimensions differ from the store
Typical cause
the embedder model changed, or the provider returned a width the embedder was not declared with. The fix used to name x ai reindex, which is planned and throws — a fix line naming it sends an operator to a wall
Fix
use the same embedder that created the store, or re-embed every record at the new width and upsert it — for a declared/returned mismatch, set dimension: on the embedder to the width cause names first