Documentation a newcomer actually needs

README.md

@@ -231,6 +231,37 @@ an impossible bound, tampers with a published value, and requires the checker to
 reject both — then confirms an isolated pair reproduces `k = 1.000000000000`
 exactly, since a lone pair has nothing to screen it.
 
+## Troubleshooting
+
+**`verify.py` reports violations** — that is the interesting outcome, and we
+want to hear about it. Sampling cannot prove the bound but it can refute it, so
+a genuine violation means the theorem is wrong. Before reporting, re-run with
+`--self-test` to confirm the checker still discriminates: a checker that has
+stopped working can produce either verdict.
+
+**`ModuleNotFoundError: numpy` from `verify.py`** — it should never import
+numpy. If it does, the file has been edited; the shipped version runs under
+`env -i /usr/bin/python3` with nothing installed, and a test asserts it imports
+no third-party module.
+
+**`loader.to_pandas` or `to_hf_dataset` raises ImportError** — those two are
+conveniences and do need `pandas` / `datasets`. Everything else, including
+`verify.py`, is standard library only.
+
+**The Hub viewer shows two configs and you wanted one table** — `regions` and
+`counterexamples` have different schemas and are deliberately separate. Pick the
+config in the viewer's dropdown, or use `load_regions()` / `load_counterexamples()`.
+
+**`export.py --check` says the data does not match** — it re-derives the files
+from the committed proof witness and compares. A mismatch means either the data
+or the witness was edited. Counterexample regeneration also needs `maxwell-lint`
+installed, since they are produced by running its reference models.
+
+**You want every certified leaf, not the 256 regions** — they are not published.
+The source proof records per-region certification plus aggregate counts, so the
+237,490 leaves are attested but not enumerated here. That is a real limit of
+this release and is stated rather than glossed.
+
 ## Provenance
 
 Exported by `export.py` from a committed proof witness produced by an