fixes #1252 problem with additionalProperties schema in jsconfig schema

src/main/java/com/networknt/schema/keyword/AdditionalPropertiesValidator.java

@@ -109,10 +109,6 @@ protected void validate(ExecutionContext executionContext, JsonNode node, JsonNo
         for (Iterator<Entry<String, JsonNode>> it = node.properties().iterator(); it.hasNext(); ) {
             Entry<String, JsonNode> entry = it.next();
             String pname = entry.getKey();
-            // skip the context items
-            if (pname.startsWith("#")) {
-                continue;
-            }
             if (!allowedProperties.contains(pname) && !handledByPatternProperties(pname)) {
                 if (!allowAdditionalProperties) {
                     executionContext.addError(error().instanceNode(node).property(pname)
@@ -156,10 +152,6 @@ public void walk(ExecutionContext executionContext, JsonNode node, JsonNode root
         // Else continue walking.
         for (Iterator<String> it = node.propertyNames().iterator(); it.hasNext(); ) {
             String pname = it.next();
-            // skip the context items
-            if (pname.startsWith("#")) {
-                continue;
-            }
             if (!allowedProperties.contains(pname) && !handledByPatternProperties(pname)) {
                 if (allowAdditionalProperties) {
                     if (additionalPropertiesSchema != null) {

src/test/java/com/networknt/schema/Issue1252Test.java

@@ -0,0 +1,93 @@
+/*
+ * Copyright (c) 2026 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.networknt.schema;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+class Issue1252Test {
+    @Test
+    void additionalPropertiesSchemaValidatesHashPrefixedProperties() {
+        String schemaData = "{\r\n"
+                + "  \"$schema\": \"http://json-schema.org/draft-07/schema#\",\r\n"
+                + "  \"type\": \"object\",\r\n"
+                + "  \"properties\": {\r\n"
+                + "    \"compilerOptions\": {\r\n"
+                + "      \"type\": \"object\",\r\n"
+                + "      \"properties\": {\r\n"
+                + "        \"paths\": {\r\n"
+                + "          \"type\": \"object\",\r\n"
+                + "          \"additionalProperties\": {\r\n"
+                + "            \"type\": \"array\",\r\n"
+                + "            \"items\": {\r\n"
+                + "              \"type\": \"string\"\r\n"
+                + "            }\r\n"
+                + "          }\r\n"
+                + "        }\r\n"
+                + "      }\r\n"
+                + "    }\r\n"
+                + "  }\r\n"
+                + "}";
+        String inputData = "{\r\n"
+                + "  \"compilerOptions\": {\r\n"
+                + "    \"paths\": {\r\n"
+                + "      \"#routes/*\": [\r\n"
+                + "        {\r\n"
+                + "          \"invalid\": null\r\n"
+                + "        }\r\n"
+                + "      ]\r\n"
+                + "    }\r\n"
+                + "  }\r\n"
+                + "}";
+
+        Schema schema = SchemaRegistry.withDefaultDialect(SpecificationVersion.DRAFT_7).getSchema(schemaData);
+        List<Error> errors = schema.validate(inputData, InputFormat.JSON);
+
+        assertFalse(errors.isEmpty());
+        Error error = errors.get(0);
+        assertEquals("/compilerOptions/paths/#routes~1*/0", error.getInstanceLocation().toString());
+        assertEquals("/properties/compilerOptions/properties/paths/additionalProperties/items/type",
+                error.getEvaluationPath().toString());
+        assertEquals("/compilerOptions/paths/#routes~1*/0: object found, string expected", error.toString());
+    }
+
+    @Test
+    void additionalPropertiesFalseRejectsHashPrefixedProperties() {
+        String schemaData = "{\r\n"
+                + "  \"$schema\": \"http://json-schema.org/draft-07/schema#\",\r\n"
+                + "  \"type\": \"object\",\r\n"
+                + "  \"additionalProperties\": false\r\n"
+                + "}";
+        String inputData = "{\r\n"
+                + "  \"#plugins/\": [\r\n"
+                + "    \"plugin\"\r\n"
+                + "  ]\r\n"
+                + "}";
+
+        Schema schema = SchemaRegistry.withDefaultDialect(SpecificationVersion.DRAFT_7).getSchema(schemaData);
+        List<Error> errors = schema.validate(inputData, InputFormat.JSON);
+
+        assertFalse(errors.isEmpty());
+        Error error = errors.get(0);
+        assertEquals("", error.getInstanceLocation().toString());
+        assertEquals("/additionalProperties", error.getEvaluationPath().toString());
+        assertEquals("#plugins/", error.getProperty());
+    }
+}