diff --git a/server/src/main/java/com/epam/aidial/core/server/util/ApplicationTypeSchemaUtils.java b/server/src/main/java/com/epam/aidial/core/server/util/ApplicationTypeSchemaUtils.java
index 0469606b..43803364 100644
--- a/server/src/main/java/com/epam/aidial/core/server/util/ApplicationTypeSchemaUtils.java
+++ b/server/src/main/java/com/epam/aidial/core/server/util/ApplicationTypeSchemaUtils.java
@@ -60,12 +60,12 @@ static String getCustomApplicationSchemaOrThrow(Config config, Application appli
     }
 
     @SuppressWarnings("unchecked")
-    private static Map<String, Object> filterProperties(Map<String, Object> customProps, String schema, String collectorName) {
+    private static Map<String, Object> filterProperties(Map<String, Object> applicationProperties, String schema, String collectorName) {
         try {
             JsonSchema appSchema = SCHEMA_FACTORY.getSchema(schema);
             CollectorContext collectorContext = new CollectorContext();
-            String customPropsJson = ProxyUtil.MAPPER.writeValueAsString(customProps);
-            Set<ValidationMessage> validationResult = appSchema.validate(customPropsJson, InputFormat.JSON,
+            String applicationPropertiesJson = ProxyUtil.MAPPER.writeValueAsString(applicationProperties);
+            Set<ValidationMessage> validationResult = appSchema.validate(applicationPropertiesJson, InputFormat.JSON,
                     e -> e.setCollectorContext(collectorContext));
             if (!validationResult.isEmpty()) {
                 throw new ApplicationTypeSchemaValidationException("Failed to validate custom app against the schema", validationResult);
@@ -76,7 +76,7 @@ private static Map<String, Object> filterProperties(Map<String, Object> customPr
             }
             Map<String, Object> result = new HashMap<>();
             for (String propertyName : propsCollector.collect()) {
-                result.put(propertyName, customProps.get(propertyName));
+                result.put(propertyName, applicationProperties.get(propertyName));
             }
             return result;
         } catch (ApplicationTypeSchemaValidationException e) {
@@ -91,6 +91,9 @@ public static Map<String, Object> getCustomServerProperties(Config config, Appli
         if (customApplicationSchema == null) {
             return Collections.emptyMap();
         }
+        if (application.getApplicationProperties() == null) {
+            throw new ApplicationTypeSchemaValidationException("Typed application's properties not set");
+        }
         return filterProperties(application.getApplicationProperties(), customApplicationSchema, "server");
     }
 
diff --git a/server/src/test/java/com/epam/aidial/core/server/function/enhancement/AppendCustomApplicationPropertiesFnTest.java b/server/src/test/java/com/epam/aidial/core/server/function/enhancement/AppendCustomApplicationPropertiesFnTest.java
index b0c8cfce..9cf05f0e 100644
--- a/server/src/test/java/com/epam/aidial/core/server/function/enhancement/AppendCustomApplicationPropertiesFnTest.java
+++ b/server/src/test/java/com/epam/aidial/core/server/function/enhancement/AppendCustomApplicationPropertiesFnTest.java
@@ -6,6 +6,7 @@
 import com.epam.aidial.core.server.Proxy;
 import com.epam.aidial.core.server.ProxyContext;
 import com.epam.aidial.core.server.util.ProxyUtil;
+import com.epam.aidial.core.server.validation.ApplicationTypeSchemaValidationException;
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.node.ObjectNode;
 import org.junit.jupiter.api.BeforeEach;
@@ -21,6 +22,7 @@
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.mockito.Mockito.eq;
 import static org.mockito.Mockito.mock;
@@ -78,6 +80,15 @@ void setUp() {
         when(context.getConfig()).thenReturn(config);
     }
 
+    @Test
+    void apply_throws_whenApplicationHasCustomSchemaIdAndNoCustomFieldsPassedAndApplicationPropertiesIsNull() {
+        when(context.getDeployment()).thenReturn(application);
+        application.setApplicationTypeSchemaId(URI.create("customSchemaId"));
+        when(config.getCustomApplicationSchema(eq(URI.create("customSchemaId")))).thenReturn(schema);
+        ObjectNode tree = ProxyUtil.MAPPER.createObjectNode();
+        assertThrows(ApplicationTypeSchemaValidationException.class, () -> function.apply(tree));
+    }
+
     @Test
     void apply_appendsCustomProperties_whenApplicationHasCustomSchemaIdAndNoCustomFieldsPassed() {
         String serverFile = "files/public/valid-file-path/valid-sub-path/valid%20file%20name2.ext";