diff --git a/scripts/lib/browser-scenario-service-workers-e2e.mjs b/scripts/lib/browser-scenario-service-workers-e2e.mjs
index bf88717ac5..4b36580390 100644
--- a/scripts/lib/browser-scenario-service-workers-e2e.mjs
+++ b/scripts/lib/browser-scenario-service-workers-e2e.mjs
@@ -144,14 +144,19 @@ export async function verifyScenarioServiceWorkers(endpoint, targetId) {
         true,
       );
     };
-    const assertRejected = async (scenario) => {
+    const assertRejected = async (scenario, expectedReason) => {
       const result = await provider.captureScenario(scenario);
       assert.equal(
         result.ok,
         false,
         "Worker-influenced capture unexpectedly succeeded",
       );
-      assert.equal(result.error.reason, "target_not_allowed");
+      assert.equal(result.error.reason, expectedReason);
+      if (expectedReason === "service_worker_blocked")
+        assert.match(
+          result.error.userMessage,
+          /environment\.service_workers to allow/,
+        );
       assert.equal(
         result.error.partialObservation.capture.browser.cleanup,
         "disconnected-external",
@@ -229,7 +234,7 @@ export async function verifyScenarioServiceWorkers(endpoint, targetId) {
       "worker",
     );
     await page.goto("about:blank");
-    await assertRejected(scenarioFor(second.origin));
+    await assertRejected(scenarioFor(second.origin), "service_worker_blocked");
     await page.goto("about:blank");
     await assertRejected(
       scenarioFor(first.origin, [
@@ -240,6 +245,7 @@ export async function verifyScenarioServiceWorkers(endpoint, targetId) {
           wait_until: "load",
         },
       ]),
+      "target_not_allowed",
     );
     await page.goto("about:blank");
     await assertRejected(
@@ -251,9 +257,13 @@ export async function verifyScenarioServiceWorkers(endpoint, targetId) {
         },
         { step_id: "loaded", action: "wait_for_timeout", duration_ms: 100 },
       ]),
+      "target_not_allowed",
     );
     await page.goto("about:blank");
-    await assertRejected(scenarioFor(`${first.origin}/frame`));
+    await assertRejected(
+      scenarioFor(`${first.origin}/frame`),
+      "target_not_allowed",
+    );
 
     const allowed = await provider.captureScenario(
       scenarioFor(second.origin, [], "allow"),
diff --git a/tests/acceptance/artifactInventoryJvmClass.test.ts b/tests/acceptance/artifactInventoryJvmClass.test.ts
index 408888ce71..51f3e01ebf 100644
--- a/tests/acceptance/artifactInventoryJvmClass.test.ts
+++ b/tests/acceptance/artifactInventoryJvmClass.test.ts
@@ -107,8 +107,8 @@ it("keeps valid JVM classes from being classified as Mach-O while identifying FA
     },
     {
       logical_path: "pkg/Big.class",
-      artifact_kind: "unknown",
-      artifact_format: "unknown",
+      artifact_kind: "resource",
+      artifact_format: "file",
     },
   ]);
   const jarClassIds = new Set(
@@ -121,7 +121,7 @@ it("keeps valid JVM classes from being classified as Mach-O while identifying FA
       .filter(({ artifact_id }) => jarClassIds.has(artifact_id))
       .map(({ format }) => format)
       .sort(),
-  ).toEqual(["file", "unknown"]);
+  ).toEqual(["file", "file"]);
 
   const mixedPath = join(directory, "mixed.zip");
   await writeFile(mixedPath, await archive([...javaEntries, ...fatControls]));
@@ -135,11 +135,10 @@ it("keeps valid JVM classes from being classified as Mach-O while identifying FA
     ),
   );
   for (const [name] of javaEntries)
-    expect(formatsByPath.get(name)).toEqual(
-      name === "Hello.class"
-        ? { artifact_kind: "resource", artifact_format: "file" }
-        : { artifact_kind: "unknown", artifact_format: "unknown" },
-    );
+    expect(formatsByPath.get(name)).toEqual({
+      artifact_kind: "resource",
+      artifact_format: "file",
+    });
   for (const [name] of fatControls)
     expect(formatsByPath.get(name)).toEqual({
       artifact_kind: "executable",
diff --git a/tests/acceptance/setup/registrationRuntimeEnvironmentCli.test.ts b/tests/acceptance/setup/registrationRuntimeEnvironmentCli.test.ts
index c3ea4ed5ae..1dc63877d7 100644
--- a/tests/acceptance/setup/registrationRuntimeEnvironmentCli.test.ts
+++ b/tests/acceptance/setup/registrationRuntimeEnvironmentCli.test.ts
@@ -175,6 +175,9 @@ cliTest(
       HOME: home,
       USERPROFILE: home,
       XDG_CONFIG_HOME: join(home, ".config"),
+      // Select an absent launcher so host-installed Hopper cannot make this
+      // configuration merge test plan an unrelated provider-environment edit.
+      HOPPER_LAUNCHER_PATH: join(home, "missing-hopper"),
     };
     const run = (args: readonly string[]) =>
       cli.run({ arguments: [...args, "--json"], cwd: home, environment });
diff --git a/tests/fixtures/browserScenarioCancellation.mjs b/tests/fixtures/browserScenarioCancellation.mjs
index 75c278f059..ecb85e608c 100644
--- a/tests/fixtures/browserScenarioCancellation.mjs
+++ b/tests/fixtures/browserScenarioCancellation.mjs
@@ -48,7 +48,16 @@ class ControlledSession {
     return 0;
   }
   events() {
-    return { retained: 0, dropped: 0, items: [] };
+    return {
+      retained: 0,
+      dropped: 0,
+      items: [],
+      omissions: {
+        by_kind: [],
+        network_transactions: [],
+        network_transaction_range: null,
+      },
+    };
   }
   async perform(action, signal) {
     assert.equal(action.action, "wait_for_timeout");