diff --git a/frontend/src/views/settings/SettingsView.vue b/frontend/src/views/settings/SettingsView.vue
index 48946c7..3aac2f3 100644
--- a/frontend/src/views/settings/SettingsView.vue
+++ b/frontend/src/views/settings/SettingsView.vue
@@ -242,10 +242,13 @@
           </v-card>
         </v-dialog>
 
-        <!-- Sync Results Snackbar -->
+        <!-- Snackbars -->
         <v-snackbar v-model="showSyncResult" :timeout="5000" color="success">
           {{ syncResultMessage }}
         </v-snackbar>
+        <v-snackbar v-model="showError" :timeout="6000" color="error">
+          {{ errorMessage }}
+        </v-snackbar>
       </v-tabs-window-item>
 
       <!-- Tab 3: Sync History -->
@@ -341,6 +344,10 @@ const deleteLoading = ref(false)
 const showSyncResult = ref(false)
 const syncResultMessage = ref('')
 
+// Error display
+const showError = ref(false)
+const errorMessage = ref('')
+
 // Sync logs
 const syncLogs = ref<SyncLogEntry[]>([])
 const logsLoading = ref(false)
@@ -420,6 +427,13 @@ async function startPlaidLink() {
   try {
     const { data: linkData } = await bankSyncApi.createLinkToken()
 
+    if (!linkData.linkToken) {
+      errorMessage.value = 'Plaid returned an empty link token. Check your Plaid credentials in appsettings.json.'
+      showError.value = true
+      plaidLoading.value = false
+      return
+    }
+
     // Dynamically load Plaid Link script
     await loadPlaidScript()
 
@@ -431,8 +445,9 @@ async function startPlaidLink() {
           connections.value.unshift(conn)
           syncIntervals[conn.id] = conn.syncIntervalMinutes
           openMappingDialog(conn)
-        } catch (err) {
-          console.error('Failed to complete Plaid link:', err)
+        } catch (err: any) {
+          errorMessage.value = err.response?.data?.error || 'Failed to complete Plaid link'
+          showError.value = true
         }
       },
       onExit: () => {
@@ -440,8 +455,9 @@ async function startPlaidLink() {
       }
     })
     plaid.open()
-  } catch (err) {
-    console.error('Failed to create link token:', err)
+  } catch (err: any) {
+    errorMessage.value = err.response?.data?.error || 'Failed to create Plaid link token. Check your Plaid credentials.'
+    showError.value = true
     plaidLoading.value = false
   }
 }
@@ -469,8 +485,9 @@ async function connectSimpleFin() {
     showSimpleFinDialog.value = false
     simpleFinToken.value = ''
     openMappingDialog(conn)
-  } catch (err) {
-    console.error('Failed to connect SimpleFIN:', err)
+  } catch (err: any) {
+    errorMessage.value = err.response?.data?.error || 'Failed to connect via SimpleFIN. Check your setup token.'
+    showError.value = true
   } finally {
     simpleFinLoading.value = false
   }
@@ -540,8 +557,9 @@ async function syncNow(conn: SyncConnection) {
     syncResultMessage.value = `Synced ${conn.institutionName}: ${data.transactionsImported} imported, ${data.transactionsSkipped} skipped`
     showSyncResult.value = true
     await loadConnections()
-  } catch (err) {
-    console.error('Sync failed:', err)
+  } catch (err: any) {
+    errorMessage.value = err.response?.data?.error || 'Sync failed'
+    showError.value = true
   } finally {
     syncingConnections[conn.id] = false
   }
diff --git a/src/Purrse.Plugins.BankSync/PlaidSyncProvider.cs b/src/Purrse.Plugins.BankSync/PlaidSyncProvider.cs
index c3e941d..15895f4 100644
--- a/src/Purrse.Plugins.BankSync/PlaidSyncProvider.cs
+++ b/src/Purrse.Plugins.BankSync/PlaidSyncProvider.cs
@@ -43,6 +43,10 @@ public class PlaidSyncProvider : IAccountSyncProvider
 
     public async Task<PlaidLinkTokenResult> CreateLinkTokenAsync(string userId)
     {
+        if (string.IsNullOrEmpty(_config.ClientId) || string.IsNullOrEmpty(_config.Secret))
+            throw new InvalidOperationException(
+                "Plaid credentials are not configured. Set BankSync:Plaid:ClientId and BankSync:Plaid:Secret in appsettings.json.");
+
         var response = await _client.LinkTokenCreateAsync(new LinkTokenCreateRequest
         {
             ClientId = _config.ClientId,