diff --git a/TablePro/Core/Database/DatabaseManager.swift b/TablePro/Core/Database/DatabaseManager.swift
index 45f096a41..1ec1a86b9 100644
--- a/TablePro/Core/Database/DatabaseManager.swift
+++ b/TablePro/Core/Database/DatabaseManager.swift
@@ -114,7 +114,20 @@ final class DatabaseManager {
         }
 
         // Create appropriate driver with effective connection
-        let driver = try DatabaseDriverFactory.createDriver(for: effectiveConnection)
+        let driver: DatabaseDriver
+        do {
+            driver = try DatabaseDriverFactory.createDriver(for: effectiveConnection)
+        } catch {
+            // Close tunnel if SSH was established
+            if connection.sshConfig.enabled {
+                Task {
+                    try? await SSHTunnelManager.shared.closeTunnel(connectionId: connection.id)
+                }
+            }
+            activeSessions.removeValue(forKey: connection.id)
+            currentSessionId = nil
+            throw error
+        }
 
         do {
             try await driver.connect()
diff --git a/TablePro/Views/Connection/ConnectionFormView.swift b/TablePro/Views/Connection/ConnectionFormView.swift
index b6abb4b49..a2de72222 100644
--- a/TablePro/Views/Connection/ConnectionFormView.swift
+++ b/TablePro/Views/Connection/ConnectionFormView.swift
@@ -1014,6 +1014,13 @@ struct ConnectionFormView: View {
                 } else {
                     Self.logger.error(
                         "Failed to connect: \(error.localizedDescription, privacy: .public)")
+                    NSApplication.shared.closeWindows(withId: "main")
+                    openWindow(id: "welcome")
+                    AlertHelper.showErrorSheet(
+                        title: String(localized: "Connection Failed"),
+                        message: error.localizedDescription,
+                        window: nil
+                    )
                 }
             }
         }
@@ -1035,6 +1042,13 @@ struct ConnectionFormView: View {
             } catch {
                 Self.logger.error(
                     "Failed to connect after plugin install: \(error.localizedDescription, privacy: .public)")
+                NSApplication.shared.closeWindows(withId: "main")
+                openWindow(id: "welcome")
+                AlertHelper.showErrorSheet(
+                    title: String(localized: "Connection Failed"),
+                    message: error.localizedDescription,
+                    window: nil
+                )
             }
         }
     }