diff --git a/scripts/summarize-jest.js b/scripts/summarize-jest.js
index d705ebd..7cbb283 100644
--- a/scripts/summarize-jest.js
+++ b/scripts/summarize-jest.js
@@ -12,8 +12,24 @@ if (!fs.existsSync(resultsPath)) {
   process.exit(0);
 }
 
-const raw = fs.readFileSync(resultsPath, 'utf-8');
-const data = JSON.parse(raw);
+// Existing but unreadable is a separate case from absent, and it was the one
+// that could still fail the job. `--forceExit` can end the process around the
+// write and leave a partial file, and a suite that fails to *run* rather than
+// to assert produces a shape the renderer below did not expect. Either crashed
+// the script, which failed a step named for summarising and buried the real
+// failure — the exact misdirection #142 fixed once already. See #178.
+//
+// The reason is reported rather than swallowed: "could not read the results
+// file" plus the parse error is diagnostic, where a silent empty summary is not.
+let data;
+try {
+  data = JSON.parse(fs.readFileSync(resultsPath, 'utf-8'));
+} catch (err) {
+  const why = `Could not read \`${resultsPath}\` — ${err.message}`;
+  report([`## ${label || 'Test'} Results`, '', why, '']);
+  console.log(`${label || 'Test'}: ${why}`);
+  process.exit(0);
+}
 
 const lines = [];
 lines.push(`## ${label || 'Test'} Results`);
@@ -29,8 +45,10 @@ lines.push('');
 if (data.numFailedTests > 0) {
   lines.push('### Failures');
   lines.push('');
-  for (const suite of data.testResults) {
-    for (const t of suite.testResults) {
+  // Defensive at every level, like summarize-playwright.js's traversal: a suite
+  // that failed to run can arrive without the array this walks.
+  for (const suite of data.testResults || []) {
+    for (const t of suite.testResults || []) {
       if (t.status === 'failed') {
         lines.push(`- **${t.fullName}**`);
         const msg = t.failureMessages && t.failureMessages[0]
diff --git a/scripts/summarize-playwright.js b/scripts/summarize-playwright.js
index 82fe5bd..62d30cd 100644
--- a/scripts/summarize-playwright.js
+++ b/scripts/summarize-playwright.js
@@ -12,8 +12,20 @@ if (!fs.existsSync(resultsPath)) {
   process.exit(0);
 }
 
-const raw = fs.readFileSync(resultsPath, 'utf-8');
-const data = JSON.parse(raw);
+// The traversal below is defensive at every level; reading was not. A run
+// killed part way through leaves a file that exists and does not parse, and
+// crashing on it fails a step named for summarising rather than for testing.
+// See #178.
+let data;
+try {
+  data = JSON.parse(fs.readFileSync(resultsPath, 'utf-8'));
+} catch (err) {
+  const why = `Could not read \`${resultsPath}\` — ${err.message}`;
+  report(['## Playwright E2E Results', '', why, '']);
+  console.log(`Playwright: ${why}`);
+  process.exit(0);
+}
+
 const stats = data.stats || {};
 
 const lines = [];