@@ -16,6 +16,7 @@
 - Support Expo Router 58 in `expoRouterIntegration`. Metro no longer warns about the removed `expo-router/build/global-state/router-store` module, and the integration creates navigation spans again ([#6923](https://github.com/getsentry/sentry-react-native/pull/6923))
 - Start the native iOS SDK from `RNSentrySDK` when `sentry.options.json` is missing or can't be parsed and the DSN is set in `configureOptions` ([#6956](https://github.com/getsentry/sentry-react-native/pull/6956))
   - The fallback options always failed to parse, so `configureOptions` never ran. Before 8.30.0 the app crashed at launch; since then the native SDK silently never started.
+- Don't crash the iOS app at launch when `sentry.options.json` contains `"dsn": null` ([#6958](https://github.com/getsentry/sentry-react-native/pull/6958))
 
 ### Internal
 
 
@@ -98,6 +98,47 @@ final class RNSentryStartFromFileTests: XCTestCase {
         XCTAssertEqual(actualOptions.environment, "new-environment")
     }
 
+    func testDoesNotStartWithNullDsnInOptionsFile() throws {
+        let path = try writeTemporaryOptionsFile("{ \"dsn\": null, \"environment\": \"environment-from-null-dsn-file\" }")
+        defer { try? FileManager.default.removeItem(atPath: path) }
+
+        var wasConfigurationCalled = false
+        RNSentrySDK.start(path, configureOptions: { options in
+            wasConfigurationCalled = true
+            XCTAssertEqual(options.environment, "environment-from-null-dsn-file")
+        })
+
+        XCTAssertTrue(wasConfigurationCalled)
+        XCTAssertFalse(SentrySDK.isEnabled)
+    }
+
+    func testDoesNotStartWhenConfigureOptionsSetsInvalidDsn() {
+        RNSentrySDK.start(getValidOptionsPath(), configureOptions: { options in
+            options.dsn = "invalid-dsn"
+        })
+
+        XCTAssertFalse(SentrySDK.isEnabled)
+    }
+
+    func testStartsFromJsAfterSkippedNativeStart() throws {
+        RNSentrySDK.start(getNonExistingOptionsPath(), configureOptions: nil)
+        XCTAssertFalse(SentrySDK.isEnabled)
+
+        var error: NSError?
+        RNSentryStart.start(options: ["dsn": "https://abcd@efgh.ingest.sentry.io/123456"], error: &error)
+
+        XCTAssertNil(error)
+        XCTAssertTrue(SentrySDK.isEnabled)
+        XCTAssertEqual(SentrySDK.internal.options.dsn, "https://abcd@efgh.ingest.sentry.io/123456")
+    }
+
+    func writeTemporaryOptionsFile(_ content: String) throws -> String {
+        let url = FileManager.default.temporaryDirectory
+            .appendingPathComponent("\(UUID().uuidString).options.json")
+        try content.write(to: url, atomically: true, encoding: .utf8)
+        return url.path
+    }
+
     func getNonExistingOptionsPath() -> String {
         return "/non-existing.options.json"
     }
 
@@ -303,6 +303,10 @@ + (void)setEventEnvironmentTag:(SentryEvent *)event
 
 + (NSString *_Nullable)getURLFromDSN:(NSString *)dsn
 {
+    // The options file may contain `"dsn": null`, which arrives here as NSNull.
+    if (![dsn isKindOfClass:[NSString class]]) {
+        return nil;
+    }
     NSURL *url = [NSURL URLWithString:dsn];
     if (!url) {
         return nil;