diff --git a/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginScreen.kt b/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginScreen.kt
index daae812..704bdbd 100644
--- a/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginScreen.kt
+++ b/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginScreen.kt
@@ -55,11 +55,13 @@ fun LoginRoute(
         onDispose(viewModel::clearSensitiveState)
     }
     val state = viewModel.uiState.collectAsStateWithLifecycle().value
+    val errorText = state.errorMessage?.let { stringResource(it.stringResource()) }
+        ?: actionError
+        ?: bootstrapError
     LoginScreen(
         profile = profile,
-        state = state.copy(
-            errorMessage = state.errorMessage ?: actionError ?: bootstrapError,
-        ),
+        state = state,
+        errorText = errorText,
         onUsernameChange = viewModel::setUsername,
         onPasswordChange = viewModel::setPassword,
         onRememberUsernameChange = viewModel::setRememberUsername,
@@ -75,6 +77,7 @@ fun LoginRoute(
 fun LoginScreen(
     profile: ProviderProfile,
     state: LoginUiState,
+    errorText: String? = null,
     onUsernameChange: (String) -> Unit,
     onPasswordChange: (String) -> Unit,
     onRememberUsernameChange: (Boolean) -> Unit,
@@ -174,7 +177,7 @@ fun LoginScreen(
                     enabled = formEnabled,
                     onCheckedChange = onAutoLoginChange,
                 )
-                state.errorMessage?.let { Text(it, color = MaterialTheme.colorScheme.error) }
+                errorText?.let { Text(it, color = MaterialTheme.colorScheme.error) }
                 ABoxButton(
                     onClick = onSubmit,
                     enabled = formEnabled && !switchingProvider,
@@ -210,6 +213,15 @@ private fun ToggleRow(
     }
 }
 
+private fun LoginErrorMessage.stringResource(): Int = when (this) {
+    LoginErrorMessage.REQUIRED_FIELDS -> R.string.login_error_required
+    LoginErrorMessage.INVALID_CREDENTIALS -> R.string.login_error_invalid_credentials
+    LoginErrorMessage.NETWORK_UNAVAILABLE -> R.string.login_error_network
+    LoginErrorMessage.SESSION_EXPIRED -> R.string.login_error_session_expired
+    LoginErrorMessage.PREFERENCES_UNAVAILABLE -> R.string.login_error_preferences
+    LoginErrorMessage.LOGIN_FAILED -> R.string.login_error_failed
+}
+
 @Composable
 private fun providerName(type: ProviderType): String = stringResource(
     when (type) {
diff --git a/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginViewModel.kt b/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginViewModel.kt
index a96a46b..5d96021 100644
--- a/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginViewModel.kt
+++ b/android/app/src/main/kotlin/com/flagship/abox/manager/ui/login/LoginViewModel.kt
@@ -71,7 +71,7 @@ class LoginViewModel @Inject constructor(
                 if (profile?.id == value.id) {
                     _uiState.value = _uiState.value.copy(
                         isLoadingPreferences = false,
-                        errorMessage = "Unable to load saved login settings",
+                        errorMessage = LoginErrorMessage.PREFERENCES_UNAVAILABLE,
                     )
                 }
             } finally {
@@ -126,7 +126,7 @@ class LoginViewModel @Inject constructor(
             state.isSubmitting ||
             state.isLoadingPreferences
         ) {
-            _uiState.value = state.copy(errorMessage = "Username and password are required")
+            _uiState.value = state.copy(errorMessage = LoginErrorMessage.REQUIRED_FIELDS)
             return
         }
         submitJob = viewModelScope.launch {
@@ -149,14 +149,23 @@ class LoginViewModel @Inject constructor(
         }
     }
 
-    private fun DomainError.toUiMessage(): String = when (this) {
-        is DomainError.Authentication -> "Invalid username or password"
-        is DomainError.Network -> "Network unavailable"
-        is DomainError.TokenInvalid -> "Session expired"
-        else -> detail ?: "Login failed"
+    private fun DomainError.toUiMessage(): LoginErrorMessage = when (this) {
+        is DomainError.Authentication -> LoginErrorMessage.INVALID_CREDENTIALS
+        is DomainError.Network -> LoginErrorMessage.NETWORK_UNAVAILABLE
+        is DomainError.TokenInvalid -> LoginErrorMessage.SESSION_EXPIRED
+        else -> LoginErrorMessage.LOGIN_FAILED
     }
 }
 
+enum class LoginErrorMessage {
+    REQUIRED_FIELDS,
+    INVALID_CREDENTIALS,
+    NETWORK_UNAVAILABLE,
+    SESSION_EXPIRED,
+    PREFERENCES_UNAVAILABLE,
+    LOGIN_FAILED,
+}
+
 data class LoginUiState(
     val username: String = "",
     val password: String = "",
@@ -164,5 +173,5 @@ data class LoginUiState(
     val autoLogin: Boolean = false,
     val isLoadingPreferences: Boolean = false,
     val isSubmitting: Boolean = false,
-    val errorMessage: String? = null,
+    val errorMessage: LoginErrorMessage? = null,
 )
diff --git a/android/app/src/main/kotlin/com/flagship/abox/manager/ui/session/AppSessionViewModel.kt b/android/app/src/main/kotlin/com/flagship/abox/manager/ui/session/AppSessionViewModel.kt
index 7525220..34da97a 100644
--- a/android/app/src/main/kotlin/com/flagship/abox/manager/ui/session/AppSessionViewModel.kt
+++ b/android/app/src/main/kotlin/com/flagship/abox/manager/ui/session/AppSessionViewModel.kt
@@ -16,6 +16,8 @@ import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.combine
+import kotlinx.coroutines.flow.distinctUntilChanged
+import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.stateIn
 import kotlinx.coroutines.launch
 
@@ -60,6 +62,33 @@ class AppSessionViewModel @Inject constructor(
                 )
             }
         }
+        viewModelScope.launch {
+            coordinator.observeActiveSession()
+                .map { it?.profileId }
+                .distinctUntilChanged()
+                .collect { sessionProfileId ->
+                    if (sessionProfileId != null && bootstrapResult.value?.profileId == sessionProfileId) {
+                        bootstrapResult.value = ProviderBootstrapResult(
+                            profileId = sessionProfileId,
+                            result = DomainResult.Success(null),
+                        )
+                    }
+                }
+        }
+        viewModelScope.launch {
+            profileStore.observeActiveProfile()
+                .map { it?.id }
+                .distinctUntilChanged()
+                .collect { activeProfileId ->
+                    val currentBootstrap = bootstrapResult.value
+                    if (currentBootstrap != null && currentBootstrap.profileId != activeProfileId) {
+                        bootstrapResult.value = ProviderBootstrapResult(
+                            profileId = activeProfileId,
+                            result = DomainResult.Success(null),
+                        )
+                    }
+                }
+        }
     }
 
     private fun stateFor(
diff --git a/android/app/src/main/res/values-zh-rCN/strings.xml b/android/app/src/main/res/values-zh-rCN/strings.xml
index 3a812f4..90e8af8 100644
--- a/android/app/src/main/res/values-zh-rCN/strings.xml
+++ b/android/app/src/main/res/values-zh-rCN/strings.xml
@@ -19,6 +19,12 @@
     <string name="login_password">密码</string>
     <string name="login_remember_username">记住用户名</string>
     <string name="login_auto_login">自动登录</string>
+    <string name="login_error_required">请输入用户名和密码。</string>
+    <string name="login_error_invalid_credentials">用户名或密码不正确。</string>
+    <string name="login_error_network">网络不可用，请重试。</string>
+    <string name="login_error_session_expired">会话已失效，请重新登录。</string>
+    <string name="login_error_preferences">无法加载已保存的登录设置。</string>
+    <string name="login_error_failed">登录失败，请重试。</string>
     <string name="action_login">登录</string>
     <string name="action_logout">退出登录</string>
     <string name="action_switch_provider">切换提供方</string>
diff --git a/android/app/src/main/res/values/strings.xml b/android/app/src/main/res/values/strings.xml
index 0a63752..a2b1d2d 100644
--- a/android/app/src/main/res/values/strings.xml
+++ b/android/app/src/main/res/values/strings.xml
@@ -19,6 +19,12 @@
     <string name="login_password">Password</string>
     <string name="login_remember_username">Remember username</string>
     <string name="login_auto_login">Sign in automatically</string>
+    <string name="login_error_required">Username and password are required.</string>
+    <string name="login_error_invalid_credentials">Invalid username or password.</string>
+    <string name="login_error_network">Network unavailable. Try again.</string>
+    <string name="login_error_session_expired">Session expired. Sign in again.</string>
+    <string name="login_error_preferences">Unable to load saved login settings.</string>
+    <string name="login_error_failed">Sign-in failed. Try again.</string>
     <string name="action_login">Sign in</string>
     <string name="action_logout">Sign out</string>
     <string name="action_switch_provider">Switch provider</string>