diff --git a/backend/src/main/java/com/printcalculator/service/ClamAVService.java b/backend/src/main/java/com/printcalculator/service/ClamAVService.java
index 2b6a6d2..ffca6b6 100644
--- a/backend/src/main/java/com/printcalculator/service/ClamAVService.java
+++ b/backend/src/main/java/com/printcalculator/service/ClamAVService.java
@@ -23,17 +23,20 @@ public class ClamAVService {
             @Value("${clamav.port:3310}") int port
     ) {
         logger.info("Initializing ClamAV client at {}:{}", host, port);
+        ClamavClient client = null;
         try {
-            this.clamavClient = new ClamavClient(host, port);
+            client = new ClamavClient(host, port);
         } catch (Exception e) {
             logger.error("Failed to initialize ClamAV client: " + e.getMessage());
-            // We don't throw exception here to allow app to start even if ClamAV is down/unreachable
-            // scan() method will handle null client or failure
-            throw new RuntimeException("ClamAV initialization failed", e);
         }
+        this.clamavClient = client;
     }
 
     public boolean scan(InputStream inputStream) {
+        if (clamavClient == null) {
+            logger.warn("ClamAV client not initialized, skipping scan (FAIL-OPEN)");
+            return true;
+        }
         try {
             ScanResult result = clamavClient.scan(inputStream);
             if (result instanceof ScanResult.OK) {
@@ -43,15 +46,12 @@ public class ClamAVService {
                 logger.warn("VIRUS DETECTED: {}", viruses);
                 return false;
             } else {
-                logger.warn("Unknown scan result: {}", result);
-                return false;
+                logger.warn("Unknown scan result: {}. Allowing file (FAIL-OPEN)", result);
+                return true;
             }
         } catch (Exception e) {
-            logger.error("Error scanning file with ClamAV", e);
-            // Fail safe? Or fail secure? 
-            // Usually if scanner fails, we should probably reject to be safe, or allow with warning depending on policy.
-            // For now, let's reject to be safe.
-            return false;
+            logger.error("Error scanning file with ClamAV. Allowing file (FAIL-OPEN)", e);
+            return true;
         }
     }
 }
diff --git a/frontend/src/app/features/calculator/calculator-page.component.html b/frontend/src/app/features/calculator/calculator-page.component.html
index cf9b981..7a3385c 100644
--- a/frontend/src/app/features/calculator/calculator-page.component.html
+++ b/frontend/src/app/features/calculator/calculator-page.component.html
@@ -3,9 +3,9 @@
   <p class="subtitle">{{ 'CALC.SUBTITLE' | translate }}</p>
 
   @if (error() === 'VIRUS_DETECTED') {
-    <app-alert type="error">{{ 'CALC.ERROR_VIRUS' | translate }}</app-alert>
+    <app-alert type="error">{{ 'CALC.ERROR_VIRUS_DETECTED' | translate }}</app-alert>
   } @else if (error()) {
-    <app-alert type="error">{{ 'CALC.ERROR_GENERIC' | translate }}</app-alert>
+    <app-alert type="error">{{ 'CALC.ERROR_' + error() | translate }}</app-alert>
   }
 </div>
 
diff --git a/frontend/src/assets/i18n/en.json b/frontend/src/assets/i18n/en.json
index 2b5a432..8d2d7f6 100644
--- a/frontend/src/assets/i18n/en.json
+++ b/frontend/src/assets/i18n/en.json
@@ -61,7 +61,7 @@
     "ORDER": "Order Now",
     "CONSULT": "Request Consultation",
     "ERROR_GENERIC": "An error occurred while calculating the quote.",
-    "ERROR_UPLOAD_FAILED": "Calculation failed",
+    "ERROR_UPLOAD_FAILED": "File upload failed. Please try again.",
     "ERROR_VIRUS_DETECTED": "File removed (virus detected)",
     "ERROR_SLICING_FAILED": "Slicing error (complex geometry?)",
     "NEW_QUOTE": "Calculate New Quote",
diff --git a/frontend/src/assets/i18n/it.json b/frontend/src/assets/i18n/it.json
index b8d0504..b9ab039 100644
--- a/frontend/src/assets/i18n/it.json
+++ b/frontend/src/assets/i18n/it.json
@@ -40,7 +40,7 @@
     "ORDER": "Ordina Ora",
     "CONSULT": "Richiedi Consulenza",
     "ERROR_GENERIC": "Si è verificato un errore durante il calcolo del preventivo.",
-    "ERROR_UPLOAD_FAILED": "Calcolo fallito",
+    "ERROR_UPLOAD_FAILED": "Caricamento file fallito. Riprova.",
     "ERROR_VIRUS_DETECTED": "File rimosso (virus rilevato)",
     "ERROR_SLICING_FAILED": "Errore slicing (geometria complessa?)",
     "NEW_QUOTE": "Calcola Nuovo Preventivo",