diff --git a/scripts/build-board.mjs b/scripts/build-board.mjs
index cbe2a61..0c58738 100644
--- a/scripts/build-board.mjs
+++ b/scripts/build-board.mjs
@@ -20,7 +20,10 @@ const f2 = x => x == null || Number.isNaN(x) ? '—' : (Math.round(x * 100) / 10
 const mean = a => a.length ? a.reduce((x, y) => x + y, 0) / a.length : null;
 
 // ---------- live measurement ----------
-const SET = resolve('levels/prototypes/d5.json');
+// The shipping set once it exists, the prototype output before that. Reading
+// the prototype after the campaign was assembled showed the tile as "18 / 50"
+// while fifty levels were sitting in levels/campaign-50.json.
+const SET = [resolve('levels/campaign-50.json'), resolve('levels/prototypes/d5.json')].find(existsSync);
 let pool = { n: 0, rot: {}, apt: null, families: {}, blind: null, wrong: null, endgame: {} };
 if (existsSync(SET)) {
   const raw = JSON.parse(readFileSync(SET, 'utf8'));
@@ -29,7 +32,7 @@ if (existsSync(SET)) {
   for (const l of levels) {
     const r = l.prototype?.stats?.rotations ?? solveRotations(l).rotations;
     pool.rot[r] = (pool.rot[r] || 0) + 1;
-    const fam = l.id.replace('proto-d5-', '').replace(/-r\d+-s\d+$/, '');
+    const fam = l.campaign?.family ?? l.id.replace('proto-d5-', '').replace(/-r\d+-s\d+$/, '');
     pool.families[fam] = (pool.families[fam] || 0) + 1;
     const a = l.prototype?.audit ?? deadTurnAudit(l);
     pool.endgame[a.endgameMinOpen] = (pool.endgame[a.endgameMinOpen] || 0) + 1;
diff --git a/src/campaign-versions.js b/src/campaign-versions.js
index b933e75..d5dacbe 100644
--- a/src/campaign-versions.js
+++ b/src/campaign-versions.js
@@ -36,6 +36,7 @@ export const CAMPAIGN_VERSIONS = [
   {
     id:C50_CAMPAIGN.id, name:C50_CAMPAIGN.name, description:C50_CAMPAIGN.description,
     chapters:C50_CAMPAIGN.chapters, chapterSize:C50_CAMPAIGN.chapterSize, levels:C50_LEVELS,
+    legacyStorageKeys:[],
   },
 ];
 export const DEFAULT_CAMPAIGN_VERSION = 'v0.5';
diff --git a/tests/campaign-versions.test.js b/tests/campaign-versions.test.js
index 0a5c0f1..94bb798 100644
--- a/tests/campaign-versions.test.js
+++ b/tests/campaign-versions.test.js
@@ -118,3 +118,20 @@ test('the production campaign starts independently and retains its thousandth le
   assert.equal(s.getItem(campaignProgressKey('v0.4')),old);
   assert.equal(selectedCampaign(s).id,'v0.5');
 });
+
+// A campaign edition is registered by hand, and app.js spreads several of its
+// fields on load. Leaving one out registers an edition that looks fine in every
+// other test and blanks the board the moment somebody opens it — which is how
+// c50 shipped its first build.
+test('every campaign edition carries the fields the app reads on load', () => {
+  for (const edition of CAMPAIGN_VERSIONS) {
+    assert.ok(edition.id && edition.name, `${edition.id}: 缺 id/name`);
+    assert.ok(Array.isArray(edition.levels) && edition.levels.length, `${edition.id}: 缺关卡`);
+    assert.ok(Array.isArray(edition.chapters) && edition.chapters.length, `${edition.id}: 缺章节`);
+    assert.ok(Number.isFinite(edition.chapterSize) && edition.chapterSize > 0, `${edition.id}: chapterSize 非法`);
+    // app.js iterates this one directly, so a missing array is a TypeError.
+    assert.ok(Array.isArray(edition.legacyStorageKeys), `${edition.id}: legacyStorageKeys 必须是数组`);
+    assert.ok(edition.chapters.length >= Math.ceil(edition.levels.length / edition.chapterSize),
+      `${edition.id}: 章节数不够放下 ${edition.levels.length} 关`);
+  }
+});