diff --git a/packages/angular_devkit/core/src/experimental/jobs/simple-scheduler_spec.ts b/packages/angular_devkit/core/src/experimental/jobs/simple-scheduler_spec.ts
index a3ddbe628c2c..4973f96531eb 100644
--- a/packages/angular_devkit/core/src/experimental/jobs/simple-scheduler_spec.ts
+++ b/packages/angular_devkit/core/src/experimental/jobs/simple-scheduler_spec.ts
@@ -102,7 +102,7 @@ describe('SimpleScheduler', () => {
       // is released, otherwise this breaks because bazel downgrade to ES5 which does not support
       // extending Error.
       // expect(e instanceof JobInboundMessageSchemaValidationError).toBe(true);
-      expect(e.message).toMatch(/"\[0\]".*number/);
+      expect(e.message).toMatch(/"\/0" must be number/);
     }
   });
 
diff --git a/packages/angular_devkit/core/src/json/schema/registry.ts b/packages/angular_devkit/core/src/json/schema/registry.ts
index 2939d91d4802..69333feb6dfb 100644
--- a/packages/angular_devkit/core/src/json/schema/registry.ts
+++ b/packages/angular_devkit/core/src/json/schema/registry.ts
@@ -6,7 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import Ajv, { ValidateFunction } from 'ajv';
+import Ajv, { SchemaObjCxt, ValidateFunction } from 'ajv';
 import ajvAddFormats from 'ajv-formats';
 import * as http from 'http';
 import * as https from 'https';
@@ -305,6 +305,8 @@ export class CoreSchemaRegistry implements SchemaRegistry {
     try {
       this._currentCompilationSchemaInfo = schemaInfo;
       validator = this._ajv.compile(schema);
+    } catch {
+      validator = await this._ajv.compileAsync(schema);
     } finally {
       this._currentCompilationSchemaInfo = undefined;
     }
@@ -406,10 +408,7 @@ export class CoreSchemaRegistry implements SchemaRegistry {
           }
 
           // We cheat, heavily.
-          const pathArray = it.dataPathArr
-            .slice(1, it.dataLevel + 1)
-            .map((p) => (typeof p === 'number' ? p : p.str.slice(1, -1)));
-
+          const pathArray = this.normalizeDataPathArr(it);
           compilationSchemInfo.smartDefaultRecord.set(JSON.stringify(pathArray), schema);
 
           return () => true;
@@ -449,12 +448,7 @@ export class CoreSchemaRegistry implements SchemaRegistry {
           return () => true;
         }
 
-        const path =
-          '/' +
-          it.dataPathArr
-            .slice(1, it.dataLevel + 1)
-            .map((p) => (typeof p === 'number' ? p : p.str.slice(1, -1)))
-            .join('/');
+        const path = '/' + this.normalizeDataPathArr(it).join('/');
 
         let type: string | undefined;
         let items: Array<string | { label: string; value: string | number | boolean }> | undefined;
@@ -593,11 +587,31 @@ export class CoreSchemaRegistry implements SchemaRegistry {
     data: any,
     fragments: string[],
     value: unknown,
-    parent: Record<string, unknown> | null = null,
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    parent: any = null,
     parentProperty?: string,
     force?: boolean,
   ): void {
-    for (const fragment of fragments) {
+    for (let index = 0; index < fragments.length; index++) {
+      const fragment = fragments[index];
+      if (/^i\d+$/.test(fragment)) {
+        if (!Array.isArray(data)) {
+          return;
+        }
+
+        for (let dataIndex = 0; dataIndex < data.length; dataIndex++) {
+          CoreSchemaRegistry._set(
+            data[dataIndex],
+            fragments.slice(index + 1),
+            value,
+            data,
+            `${dataIndex}`,
+          );
+        }
+
+        return;
+      }
+
       if (!data && parent !== null && parentProperty) {
         data = parent[parentProperty] = {};
       }
@@ -665,4 +679,10 @@ export class CoreSchemaRegistry implements SchemaRegistry {
       );
     }
   }
+
+  private normalizeDataPathArr(it: SchemaObjCxt): (number | string)[] {
+    return it.dataPathArr
+      .slice(1, it.dataLevel + 1)
+      .map((p) => (typeof p === 'number' ? p : p.str.replace(/\"/g, '')));
+  }
 }
diff --git a/packages/angular_devkit/core/src/json/schema/registry_spec.ts b/packages/angular_devkit/core/src/json/schema/registry_spec.ts
index 2ce888f74f9e..d64d96238d09 100644
--- a/packages/angular_devkit/core/src/json/schema/registry_spec.ts
+++ b/packages/angular_devkit/core/src/json/schema/registry_spec.ts
@@ -30,7 +30,7 @@ describe('CoreSchemaRegistry', () => {
             },
           },
           tslint: {
-            $ref: 'https://json.schemastore.org/tslint#',
+            $ref: 'https://json.schemastore.org/npm-link-up#',
           },
         },
       })
@@ -130,7 +130,7 @@ describe('CoreSchemaRegistry', () => {
         map((result) => {
           expect(result.success).toBe(false);
           expect(result.errors && result.errors[0].message).toContain(
-            'should NOT have additional properties',
+            'must NOT have additional properties',
           );
         }),
       )
@@ -180,10 +180,10 @@ describe('CoreSchemaRegistry', () => {
         mergeMap((validator) => validator(data)),
         map((result) => {
           expect(result.success).toBe(false);
-          expect(result.errors && result.errors[0].message).toContain(
-            'should NOT have additional properties',
+          expect(result.errors?.[0].message).toContain(
+            'must NOT have additional properties',
           );
-          expect(result.errors && result.errors[0].keyword).toBe('additionalProperties');
+          expect(result.errors?.[0].keyword).toBe('additionalProperties');
         }),
       )
       .toPromise()
@@ -249,7 +249,7 @@ describe('CoreSchemaRegistry', () => {
       .then(done, done.fail);
   });
 
-  it('shows dataPath and message on error', (done) => {
+  it('shows dataPath and message on error', async () => {
     const registry = new CoreSchemaRegistry();
     const data = { hotdot: 'hotdog', banana: 'banana' };
     const format: SchemaFormat = {
@@ -262,7 +262,7 @@ describe('CoreSchemaRegistry', () => {
 
     registry.addFormat(format);
 
-    registry
+    await registry
       .compile({
         properties: {
           hotdot: { type: 'string', format: 'is-hotdog' },
@@ -275,12 +275,11 @@ describe('CoreSchemaRegistry', () => {
           expect(result.success).toBe(false);
           expect(result.errors && result.errors[0]).toBeTruthy();
           expect(result.errors && result.errors[0].keyword).toBe('format');
-          expect(result.errors && result.errors[0].instancePath).toBe('.banana');
+          expect(result.errors && result.errors[0].instancePath).toBe('/banana');
           expect(result.errors && (result.errors[0].params as any).format).toBe('is-hotdog');
         }),
       )
       .toPromise()
-      .then(done, done.fail);
   });
 
   it('supports smart defaults', (done) => {