diff --git a/lib/src/main/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactory.java b/lib/src/main/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactory.java
index e09f5d96..b4aea3a7 100644
--- a/lib/src/main/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactory.java
+++ b/lib/src/main/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactory.java
@@ -24,6 +24,7 @@
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import javax.annotation.Nullable;
@@ -78,6 +79,8 @@ IsolatedLauncherAndClassloader createLauncher(final LegacyScannerEngineDownloade
       tempCleaning.clean();
 
       return new IsolatedLauncherAndClassloader(objProxy, cl, jarFiles.stream().allMatch(CachedFile::isCacheHit));
+    } catch (IllegalStateException e) {
+      throw new ScannerException("Unable to execute SonarScanner analysis: " + Optional.ofNullable(e.getCause()).map(Throwable::getMessage).orElse(e.getMessage()));
     } catch (Exception e) {
       // Catch all other exceptions, which relates to reflection
       throw new ScannerException("Unable to execute SonarScanner analysis", e);
diff --git a/lib/src/main/java/org/sonarsource/scanner/lib/internal/ScannerException.java b/lib/src/main/java/org/sonarsource/scanner/lib/internal/ScannerException.java
index a5300075..097958f0 100644
--- a/lib/src/main/java/org/sonarsource/scanner/lib/internal/ScannerException.java
+++ b/lib/src/main/java/org/sonarsource/scanner/lib/internal/ScannerException.java
@@ -21,6 +21,10 @@
 
 public class ScannerException extends RuntimeException {
 
+  public ScannerException(String message) {
+    super(message);
+  }
+
   public ScannerException(String message, Throwable cause) {
     super(message, cause);
   }
diff --git a/lib/src/test/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactoryTest.java b/lib/src/test/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactoryTest.java
index 1fb478f3..d0edc101 100644
--- a/lib/src/test/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactoryTest.java
+++ b/lib/src/test/java/org/sonarsource/scanner/lib/internal/IsolatedLauncherFactoryTest.java
@@ -19,6 +19,7 @@
  */
 package org.sonarsource.scanner.lib.internal;
 
+import java.net.ConnectException;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Properties;
@@ -27,8 +28,9 @@
 import org.sonarsource.scanner.lib.internal.batch.IsolatedLauncher;
 import org.sonarsource.scanner.lib.internal.batch.LogOutput;
 
-import static org.junit.jupiter.api.Assertions.assertThrows;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 
 class IsolatedLauncherFactoryTest {
   IsolatedLauncherFactory factory;
@@ -37,7 +39,7 @@ class IsolatedLauncherFactoryTest {
   LegacyScannerEngineDownloader legacyScannerEngineDownloader;
 
   @BeforeEach
-  public void setUp() {
+  void setUp() {
     tempCleaning = mock(TempCleaning.class);
     factory = new IsolatedLauncherFactory(FakeIsolatedLauncher.class.getName(), tempCleaning);
     props = new Properties();
@@ -46,10 +48,19 @@ public void setUp() {
 
   @Test
   void should_use_isolated_classloader() {
-    var rules = new ClassloadRules(new HashSet<String>(), new HashSet<String>());
-    assertThrows(ScannerException.class, () -> {
-      factory.createLauncher(legacyScannerEngineDownloader, rules);
-    });
+    var rules = new ClassloadRules(new HashSet<>(), new HashSet<>());
+    assertThatThrownBy(() -> factory.createLauncher(legacyScannerEngineDownloader, rules))
+      .isInstanceOf(ScannerException.class);
+  }
+
+  @Test
+  void should_omit_connection_error_exceptions_and_return_error_message() {
+    when(legacyScannerEngineDownloader.getOrDownload()).thenThrow(
+      new IllegalStateException("Fail to get bootstrap index from server", new ConnectException("Failed to connect to localhost/127.0.0.1:9000"))
+    );
+    assertThatThrownBy(() -> factory.createLauncher(legacyScannerEngineDownloader, new ClassloadRules(new HashSet<>(), new HashSet<>())))
+      .isInstanceOf(ScannerException.class)
+      .hasMessage("Unable to execute SonarScanner analysis: Failed to connect to localhost/127.0.0.1:9000");
   }
 
   public static class FakeIsolatedLauncher implements IsolatedLauncher {